2023年07月, 日本機械学会 流体工学部門, フロンティア表彰
気液界面熱物質輸送に関する分子流体力学解析
小林一道, 33844587

2021年04月, Nature Portfolio, Top 100 in Physics
Evaporation coefficient and condensation coefficient of vapor under high gas pressure conditions
Kotaro Ohashi;Kazumichi Kobayashi;Hiroyuki Fujii;Masao Watanabe, 28160290

2008年04月, 日本機械学会, 日本機械学会賞（論文）　　　　　　　　　　　　　　　
衝撃波管管端でのメタノール蒸気の凝縮過程に関する分子気体力学解析
日本国

2007年03月, 日本熱物性学会, ベストプレゼンテーション賞　　　　　　　　　　　　　　　
衝撃波管管端で起こる膜状凝縮によって測定された水の凝縮係数
小林 一道

2005年06月, The 1st CRIS International Symposium on Computational Science and Neuroscience, Top Poster Award　　　　　　　　　　　　　　　
Determination of Condensation Coefficient of Methanol by Combining Molecular Gas Dynamics Simulation and Shock Tube Experiment
Kazumichi Kobayashi

Particle size distribution effects on the light scattering properties in non-diluted colloidal suspensions: A numerical study
Hiroyuki Fujii, Hyeonwoo Na, Jungyun Yi, Kazumichi Kobayashi, Masao Watanabe
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 135208, 135208, Elsevier BV, 2024年08月
研究論文（学術雑誌）

Interference effects on light scattering properties of dense colloidal suspensions: a short review
Hiroyuki Fujii, Hyeonwoo Na, Koyata Nishikawa, Kazumichi Kobayashi, Masao Watanabe
Optical Review, 31, 3, 299, 308, Springer Science and Business Media LLC, 2024年05月22日
研究論文（学術雑誌）, Abstract

Near-infrared spectroscopy and imaging using scattered light potentially evaluate the structural properties of the medium, like the average particle size, based on a relation between its structure and light scattering. A qualitative understanding of light scattering is crucial for developing optical imaging techniques. The scattering properties of dense colloidal suspensions have been extensively investigated using the electromagnetic theory (EMT). The colloidal suspensions are widely used in liquid tissue phantoms for optical imaging techniques and are encountered in various fields, such as the food and chemical industries. The interference between electric fields scattered by colloidal particles significantly influences the scattering properties, so-called the interference effects. Despite many efforts since the 1980s, a complete understanding of the interference effects has still not been achieved. The main reason is the complicated dependence of the interference on the optical wavelength, particle size, and so on. This paper briefly reviews numerical and theoretical studies of the interference effect based on the dependent scattering theory, one of the EMTs, and model equations.

Couette flow at high Knudsen number between wall and liquid boundaries
Kazumichi Kobayashi, Kota Aoki, Hirofumi Tabe, Hiroyuki Fujii, Toshiki Nara, Hideyoshi Takashima, Nobuyuki Oshima, Masao Watanabe
Physics of Fluids, 35, 8, 082021, 082021, AIP Publishing, 2023年08月01日, ［査読有り］, ［筆頭著者, 責任著者］
英語, 研究論文（学術雑誌）, This paper presents molecular dynamics simulations of the Couette flow of a rarefied gas between the liquid and wall boundaries and, in particular, investigates the boundary conditions for the Boltzmann equation at the liquid interface. The simulation results for various Knudsen numbers show that the slip velocity decreases at the liquid boundary and increases at the smooth wall as the Knudsen number increases, indicating that the velocity profile of the rarefied Couette flow is asymmetric. One reason for this is backscattering, in which molecules are reflected in the opposite direction to the mainstream flow, owing to molecular-scale roughness at the liquid boundary. It has also been suggested that the backscattering effect decreases when the gas density increases. This can be understood using the local Knudsen numbers near the liquid boundary., 33844587

Numerical study of light scattering and propagation in soymilk: Effects of particle size distributions, concentrations, and medium sizes
Hiroyuki Fujii, Koyata Nishikawa, Hyeonwoo Na, Yuki Inoue, Kazumichi Kobayashi, Masao Watanabe
Infrared Physics & Technology, 132, 104753, 104753, Elsevier BV, 2023年08月
研究論文（学術雑誌）

Vapor condensation induced by fast-moving liquid film in the presence of noncondensable gas molecules
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
International Communications in Heat and Mass Transfer, 142, 106622, 106622, Elsevier BV, 2023年03月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）, 33844587

Molecular dynamics study of evaporation induced by locally heated argon liquid
Hirofumi Tabe, Kiryu Hiramatsu, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe, Tsuyoshi Totani
Applied Thermal Engineering, 212, 118472, 118472, Elsevier BV, 2022年07月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）, 33844587

Wetting failure in the early stage of water drop impact on a smooth solid surface
Ryunosuke Adachi, Kazumichi Kobayashi, Hiroyuki Fujii, Toshiyuki Sanada, Masao Watanabe
Physics of Fluids, 34, 6, 062116, 062116, AIP Publishing, 2022年06月, ［査読有り］
英語, 研究論文（学術雑誌）, A water drop impacting a dry solid surface can eject a thin liquid sheet, which is forced to expand on the surface to wet the solid surface. Wetting failure, which produces defects in applications based on the impact of drops, including coating, cooling, cleaning, and printing, may occur with a sufficiently large liquid-sheet velocity. However, the exact onset of wetting failure when a drop impacts the surface has yet to be determined. Therefore, we examine the dependence of rim instability immediately after liquid-sheet ejection on the static contact angle of the solid surface at the instant of water drop impact. This study is the first attempt to solve this problem and is made possible only by using an ultra-high-speed camera. We revealed that wetting failure can occur by investigating the rim instability of the liquid sheet.

Modeling photoacoustic pressure generation in colloidal suspensions at different volume fractions based on a multi-scale approach
Hiroyuki Fujii, Iori Terabayashi, Kazumichi Kobayashi, Masao Watanabe
Photoacoustics, 27, 100368, 100368, Elsevier BV, 2022年06月, ［査読有り］
英語, 研究論文（学術雑誌）

Molecular dynamics simulation of evaporation coefficient of vapor molecules during steady net evaporation in binary mixture system
Hirofumi Tabe, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
International Journal of Heat and Mass Transfer, 188, 122663, 122663, Elsevier BV, 2022年06月01日, ［査読有り］, ［国際誌］
英語, 研究論文（学術雑誌）, 33844587

Model equations of light scattering properties and a characteristic time of light propagation for polydisperse colloidal suspensions at different volume fractions
Hiroyuki Fujii, Moegi Ueno, Yuki Inoue, Toshiaki Aoki, Kazumichi Kobayashi, Masao Watanabe
Optics Express, 30, 3, 3538, 3538, The Optical Society, 2022年01月31日, ［査読有り］
英語, 研究論文（学術雑誌）

Numerical Study of Near-Infrared Light Propagation in Aqueous Alumina Suspensions Using the Steady-State Radiative Transfer Equation and Dependent Scattering Theory
Hiroyuki Fujii, Iori Terabayashi, Toshiaki Aoki, Yuki Inoue, Hyeonwoo Na, Kazumichi Kobayashi, Masao Watanabe
Applied Sciences, 12, 3, 1190, 1190, MDPI AG, 2022年01月24日, ［査読有り］
英語, 研究論文（学術雑誌）, Understanding light propagation in liquid phantoms, such as colloidal suspensions, involves fundamental research of near-infrared optical imaging and spectroscopy for biological tissues. Our objective is to numerically investigate light propagation in the alumina colloidal suspensions with the mean alumina particle diameter of 55 nm at the volume fraction range 1–20%. We calculated the light scattering properties using the dependent scattering theory (DST) on a length scale comparable to the optical wavelength. We calculated the steady-state radiative transfer and photon diffusion equations (RTE and PDE) using the DST results based on the finite difference method in a length scale of the mean free path. The DST calculations showed that the scattering and reduced scattering coefficients become more prominent at a higher volume fraction. The anisotropy factor is almost zero at all the volume fractions, meaning the scattering is isotropic. The comparative study of the RTE with the PDE showed that the diffusion approximation holds at the internal region with all the volume fractions and the boundary region with the volume fraction higher than 1%. Our findings suggest the usefulness of the PDE as a light propagation model for the alumina suspensions rather than the RTE, which provides accurate but complicated computation.

Mean-field kinetic theory analysis of vapor flow between evaporating and condensing interfaces in the presence of non-condensable gas molecules
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
Physics of Fluids, 33, 12, 122017, 122017, AIP Publishing, 2021年12月22日, ［査読有り］, ［責任著者］, ［国際誌］
英語, 研究論文（学術雑誌）, 28160290

Molecular dynamics study on characteristics of reflection and condensation molecules at vapor–liquid equilibrium state
Hirofumi Tabe, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
PLOS ONE, 16, 3, e0248660, e0248660, Public Library of Science (PLoS), 2021年03月16日, ［査読有り］
英語, 研究論文（学術雑誌）, The kinetic boundary condition (KBC) represents the evaporation or condensation of molecules at the vapor–liquid interface for molecular gas dynamics (MGD). When constructing the KBC, it is necessary to classify molecular motions into evaporation, condensation, and reflection in molecular-scale simulation methods. Recently, a method that involves setting the vapor boundary and liquid boundary has been used for classifying molecules. The position of the vapor boundary is related to the position where the KBC is applied in MGD analyses, whereas that of the liquid boundary has not been uniquely determined. Therefore, in this study, we conducted molecular dynamics simulations to discuss the position of the liquid boundary for the construction of KBCs. We obtained some variables that characterize molecular motions such as the positions that the molecules reached and the time they stayed in the vicinity of the interface. Based on the characteristics of the molecules found from these variables, we investigated the valid position of the liquid boundary. We also conducted an investigation on the relationship between the condensation coefficient and the molecular incident velocity from the vapor phase to the liquid phase. The dependence of the condensation coefficient on the incident velocity of molecules was confirmed, and the value of the condensation coefficient becomes small in the low-incident-velocity range. Furthermore, we found that the condensation coefficient in the non-equilibrium state shows almost the same value as that in the equilibrium state, although the corresponding velocity distribution functions of the incident velocity significantly differ from each other., 28160290

A comparative study of the delta-Eddington and Galerkin quadrature methods for highly forward scattering of photons in random media
Hiroyuki Fujii, Go Chiba, Yukio Yamada, Yoko Hoshi, Kazumichi Kobayashi, Masao Watanabe
Journal of Computational Physics, 423, 109825, 109825, Elsevier BV, 2020年09月, ［査読有り］
英語, 研究論文（学術雑誌）

Photon transport model for dense polydisperse colloidal suspensions using the radiative transfer equation combined with the dependent scattering theory
Hiroyuki Fujii, Leung Tsang, Jiyue Zhu, Koki Nomura, Kazumichi Kobayashi, Masao Watanabe
Optics Express, The Optical Society, 2020年07月10日, ［査読有り］
研究論文（学術雑誌）

Evaporation coefficient and condensation coefficient of vapor under high gas pressure conditions
Kotaro Ohash, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
Scientific Reports, 10, 8143, 2020年05月, ［査読有り］, ［責任著者］
英語, 研究論文（学術雑誌）

Levitation mechanism of impacting nanodroplet on heated wall
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe
International Journal of Thermal Science, 150, 106203, 106203, Elsevier BV, 2020年04月, ［査読有り］
英語, 研究論文（学術雑誌）

Hidden prompt splashing by corona splashing at drop impact on a smooth dry surface
Taku Ashida, Masao Watanabe, Kazumichi Kobayashi, Hiroyuki Fujii, Toshiyuki Sanada
Physical Review Fluids, 5, 1, American Physical Society (APS), 2020年01月15日, ［査読有り］
英語, 研究論文（学術雑誌）

Characteristic length and time scales of the highly forward scattering of photons in random media　　　　　　　　　　　　　　　
Hiroyuki Fujii, Moegi Ueno, Kazumichi Kobayashi, Masao Watanabe
Applied Sciences, 10, 93, 2020年, ［査読有り］
英語

Influence of a small amount of non-condensable gas on shock wave generation inside a collapsing vapor bubble
Kyohei Yamamoto, Kazumichi Kobayashi, Masao Watanabe, Hiroyuki Fujii, Misaki Kon, Hiroyuki Takahira
Physical Review Fluids, 4, 6, 063603, 2019年06月, ［査読有り］
英語, 研究論文（学術雑誌）

Influence of liquid–solid intermolecular force on levitation of impacting nanodroplet
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe
Heat and Mass Transfer, 55, 4, 993, 1003, Springer Science and Business Media LLC, 2019年04月, ［査読有り］
英語, 研究論文（学術雑誌）

Molecular gas dynamics analysis on condensation coefficient of vapour during gas-vapour bubble collapse
Kazumichi Kobayashi, Takahiro Nagayama, Masao Watanabe, Hiroyuki Fujii, Misaki Kon
Journal of Fluid Mechanics, 856, 1045, 1063, 2018年12月, ［査読有り］
英語, 研究論文（学術雑誌）

Pressure generated at the instant of impact between a liquid droplet and solid surface
Yuki Tatekura, Masao Watanabe, Kazumichi Kobayashi, Toshiyuki Sanada
Royal Society Open Science, 5, 181101, 2018年12月, ［査読有り］
英語, 研究論文（学術雑誌）

Accurate and efficient computation of the 3D radiative transfer equation in highly forward-peaked scattering media using a renormalization approach
Hiroyuki Fujii, YukioYamad, Go Chiba, Yoko Hoshi, Kazumichi Kobayashi, Masao Watanabea
Journal of Computational Physics, 2018年07月, ［査読有り］
英語, 研究論文（学術雑誌）

Light propagation model of titanium dioxide suspensions in water using the radiative transfer equation
Hiroyuki Fujii, Yukio Yamada, Yoko Hoshi, Shinpei Okawa, Kazumichi Kobayashi, Masao Watanabe
Reaction Kinetics, Mechanisms and Catalysis, 123, 2, 439, 453, Springer Netherlands, 2018年04月01日, ［査読有り］
英語, 研究論文（学術雑誌）, Constructions of numerical schemes for solving the radiative transfer equation (RTE) are crucial to evaluate light propagation inside photocatalytic systems. We develop accurate and efficient schemes of the three-dimensional and time-dependent RTE for numerical phantoms modeling aqueous titanium dioxide suspensions, in which the anisotropy of the forward-directed scattering varies and the strength of absorption is comparable to that of scattering. To improve the accuracy and efficiency of the numerical solutions, the forward-directed phase function is renormalized in the zeroth or first order with a small number of discrete angular directions. Then, we investigate the influences of the forward-directed scattering on the numerical solutions by comparing with the analytical solutions. The investigation shows that with the anisotropy factor less than approximately 0.7 corresponding to the moderate forward-directed scattering, the numerical solutions of the RTE using the both of the zeroth and first order renormalization approaches are accurate due to the reductions of the numerical errors of the phase function. With the anisotropy factor more than approximately 0.7 corresponding to the highly forward-directed scattering, the first order renormalization approach still provides the accurate results, while the zeroth order approach does not due to the large errors of the phase function. These results suggest that the developed scheme using the first order renormalization can provide accurate and efficient calculations of light propagation in photocatalytic systems.

集束超音波と液面の干渉による微細液滴の生成
世古和也, 小林一道, 藤井宏之, 渡部正夫
混相流, 32, 1, 59, 64, 2018年, ［査読有り］, ［招待有り］
日本語

Kinetic boundary condition in vapor-liquid two-phase system during unsteady net evaporation/condensation
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS, 64, 81, 92, ELSEVIER SCIENCE BV, 2017年07月, ［査読有り］, ［招待有り］
英語, 研究論文（学術雑誌）, Heat and mass transfer caused by nonequilibrium phase change (net evaporation/condensation) play a major role in a vapor-liquid two-phase flow. In general, liquid temperature changes with time because of the heat and mass transfer between the vapor and liquid phases; however, a precise investigation of the transport phenomena related to this temporal evolution of liquid temperature is still lacking. The aim of this study is to examine a kinetic boundary condition, which depends on liquid temperature, for the Boltzmann equation in a vapor-liquid two-phase system with unsteady net evaporation/condensation. In this study, we confirmed whether the kinetic boundary condition follows the temporal evolution of liquid temperature attributed to unsteady net evaporation/condensation by using the molecular simulation based on mean-field kinetic theory, and then we validated the accuracy of the kinetic boundary condition by solving the initial boundary value problem of the Boltzmann equation in unsteady net evaporation/condensation. These results showed that the kinetic boundary condition follows the temporal evolution of liquid temperature in the simulation setting of this study. Furthermore, we concluded that the kinetic boundary condition that depends on liquid temperature is guaranteed to be accurate even in unsteady net evaporation/condensation by considering the temporal evolution of liquid temperature. (C) 2016 Elsevier Masson SAS. All rights reserved.

Modeling of light propagation in the human neck for diagnoses of thyroid cancers by diffuse optical tomography
H. Fujii, Y. Yamada, K. Kobayashi, M. Watanabe, Y. Hoshi
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, 33, 5, WILEY, 2017年05月, ［査読有り］
英語, 研究論文（学術雑誌）, Diffuse optical tomography using near-infrared light in a wavelength range from 700 to 1000nm has the potential to enable non-invasive diagnoses of thyroid cancers; some of which are difficult to detect by conventional methods such as ultrasound tomography. Diffuse optical tomography needs to be based on a physically accurate model of light propagation in the neck, because it reconstructs tomographic images of the optical properties in the human neck by inverse analysis. Our objective here was to investigate the effects of three factors on light propagation in the neck using the 2D time-dependent radiative transfer equation: (1) the presence of the trachea, (2) the refractive-index mismatch at the trachea-tissue interface, and (3) the effect of neck organs other than the trachea (spine, spinal cord, and blood vessels). There was a significant influence of reflection and refraction at the trachea-tissue interface on the light intensities in the region between the trachea and the front of the neck surface. Organs other than the trachea showed little effect on the light intensities measured at the front of the neck surface although these organs affected the light intensities locally. These results indicated the necessity of modeling the refractive-index mismatch at the trachea-tissue interface and the possibility of modeling other neck organs simply as a homogeneous medium when the source and detectors were far from large blood vessels.

Kinetic boundary conditions for vapor-gas binary mixture
Kazumichi Kobayashi, Kiyofumi Sasaki, Misaki Kon, Hiroyuki Fujii, Masao Watanabe
MICROFLUIDICS AND NANOFLUIDICS, 21, 3, 1, 13, SPRINGER HEIDELBERG, 2017年03月, ［査読有り］
英語, 研究論文（学術雑誌）, Using molecular dynamics simulations, the present study investigated the precise characteristics of the binary mixture of condensable gas (vapor) and noncondensable gas (NC gas) molecules creating kinetic boundary conditions (KBCs) at a gas-liquid interface in equilibrium. We counted the molecules utilizing the improved two-boundary method proposed in previous studies by Kobayashi et al. (Heat Mass Trans 52: 1851-1859, 2016. doi: 10.1007/s00231-015-1700-6). In this study, we employed Ar for the vapor molecules, and Ne for the NC gas molecules. The present method allowed us to count easily the evaporating, condensing, degassing, dissolving, and reflecting molecules in order to investigate the detailed motion of the molecules, and also to evaluate the velocity distribution function of the KBCs at the interface. Our results showed that the evaporation and condensation coefficients for vapor and NC gas molecules decrease with the increase in the molar fraction of the NC gas molecules in the liquid. We also found that the KBCs can be specified as a function of the molar fraction and liquid temperature. Furthermore, we discussed the method to construct the KBCs of vapor and NC gas molecules.

Molecular dynamics study on evaporation and reflection of monatomic molecules to construct kinetic boundary condition in vapor-liquid equilibria
Kazumichi Kobayashi, Kazumasa Hori, Misaki Kon, Kiyofumi Sasaki, Masao Watanabe
HEAT AND MASS TRANSFER, 52, 9, 1851, 1859, SPRINGER, 2016年09月, ［査読有り］
英語, 研究論文（学術雑誌）, Using molecular dynamics simulations, the present study investigates the precise characteristics of evaporating and reflecting monatomic molecules (argon) composing a kinetic boundary condition (KBC) in a vapor-liquid equilibria. We counted the evaporating and reflecting molecules utilizing two boundaries (vapor and liquid boundaries) proposed by the previous studies (Meland et al. in Phys Fluids 16:223-243, 2004; Gu et al. in Fluid Phase Equilib 297:77-89, 2010). In the present study, we improved the method using the two boundaries incorporating the concept of the spontaneously evaporating molecular mass flux. The present method allows us to count the evaporating and reflecting molecules easily, to investigate the detail motion of the evaporating and reflecting molecules, and also to evaluate the velocity distribution function of the KBC at the vapor-liquid interface, appropriately. From the results, we confirm that the evaporating and reflecting molecules in the normal direction to the interface have slightly faster and significantly slower average velocities than that of the Maxwell distribution at the liquid temperature, respectively. Also, the stall time of the reflecting molecules at the interphase that is the region in the vicinity of the vapor-liquid interface is much shorter than those of the evaporating molecules. Furthermore, we discuss our method for constructing the KBC that incorporates condensation and evaporation coefficients. Based on these results, we suggest that the proposed method is appropriate for investigating KBC in various nonequilibrium states or multi-component systems.

Liquid temperature dependence of kinetic boundary condition at vapor-liquid interface
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 99, 317, 326, PERGAMON-ELSEVIER SCIENCE LTD, 2016年08月, ［査読有り］
英語, 研究論文（学術雑誌）, For the accurate description of heat and mass transfer through a vapor-liquid interface, the appropriate modeling of the interface during nonequilibrium phase change (net evaporation/condensation) is a crucial issue. The aim of this study is to propose a microscopic interfacial model which should be imposed at the interface as the kinetic boundary condition for the Boltzmann equation. In this study, we constructed the kinetic boundary condition for monoatomic molecules over a wide range of liquid temperature based on mean field kinetic theory, and we validated the accuracy of the constructed kinetic boundary condition by solving the boundary value problem of the Boltzmann equation. These results showed that we can impose the kinetic boundary condition at the interface by simply specifying liquid temperature and simulate the complex vapor-liquid two-phase flow induced by net evaporation/condensation. Furthermore, we applied the constructed kinetic boundary condition to the boundary condition for the fluid-dynamic type equations. This application enables us to deal with a large spatio-temporal scale of the interfacial dynamics in the vapor-liquid two-phase system with net evaporation/condensation. (C) 2016 Elsevier Ltd. All rights reserved.

Early stage of nanodroplet impact on solid wall
Kazumichi Kobayashi, Kazuki Konno, Hisao Yaguchi, Hiroyuki Fujii, Toshiyuki Sanada, Masao Watanabe
PHYSICS OF FLUIDS, 28, 3, 032002, AMER INST PHYSICS, 2016年03月, ［査読有り］
英語, 研究論文（学術雑誌）, In this study, we investigated nanodroplet spreading at the early stage after the impact using molecular dynamics simulations by changing the magnitude of the intermolecular force between the liquid and wall molecules. We showed that the droplet deformation after the impact greatly depends on the intermolecular force. The temporal evolution of the spreading diameters was measured by the cylindrical control volume for several molecular layers in the vicinity of the wall. At the early stage of the nanodroplet impact, the normalized spreading radius of the droplet is proportional to the square root of the normalized time, (t) over cap. This result is understood by the geometrical consideration presented by Rioboo et al. ["Time evolution of liquid drop impact onto solid, dry surfaces," Exp. Fluids 33, 112-124 (2002)]. In addition, we found that as the intermolecular force between the liquid and wall becomes stronger, the normalized spreading diameter of the first molecular layer on the wall remains less dependent on the impact velocity. Furthermore, the time evolution of the droplet spreading changes from root(t) over cap to log (t) over cap with time. (C) 2016 AIP Publishing LLC.

非平衡蒸発・凝縮下の気液界面における蒸発流束の評価
今 美沙紀, 小林 一道, 佐々木 清文, 渡部 正夫
混相流, 29, 5, 493, 500, 日本混相流学会, 2016年03月, ［査読有り］, ［招待有り］
日本語, 研究論文（学術雑誌）, The aim of this study is to confirm the existence of a spontaneous evaporation molecular mass flux which takes a constant value independent of the degree of net evaporation/condensation. We carried out the numerical simulation based on the mean field kinetic theory during net evaporation/condensation and estimated the evaporation and reflection molecular mass fluxes by using a pair of boundaries. The simulation results showed that the reflection molecular mass flux varies with the increase of the degree of nonequilibrium, and the evaporation molecular mass flux takes a constant value during net evaporation and condensation.

Study on Pressure Wave Propagation in a Liquid Containing Spherical Bubbles in a Rectangular Duct
Junya Kawahara, Masao Watanabe, Kazumichi Kobayashi
Journal of Physics: Conference Series, 656, 012023, 012023, IOP Publishing, 2015年12月03日, ［査読有り］
英語, 研究論文（学術雑誌）, Pressure wave propagation in a liquid containing several bubbles is numerically investigated. We simulate liner plane wave propagation in a liquid containing 10 spherical bubbles in a rectangular duct with the equation of motion for N spherical bubbles. The sound pressures of the reflected waves from the rigid walls are calculated by using the method of images. The result shows that the phase velocity of the pressure wave propagating in the liquid containing 10 spherical bubbles in the duct agrees well with the low-frequency speed of sound in a homogeneous bubbly liquid.

Numerical simulation of bubble collapse and the transfer of vapor and noncondensable gas through the bubble interface using the ghost fluid method
Y Jinbo, K Kobayashi, M Watanabe, H Takahira
Journal of Physics: Conference Series, 656, 012021, 012021, IOP Publishing, 2015年12月03日, ［査読有り］
英語, 研究論文（学術雑誌）, The ghost fluid method is improved to include heat and mass transfer across the gas-liquid interface during the bubble collapse in a compressible liquid. This transfer is due to both nonequilibrium phase transition at the interface and diffusion of the noncondensable gas across the interface. In the present method, the ghost fluids are defined with the intention of conserving the total mass, momentum, and energy, as well as the mass of each component while considering the heat and mass fluxes across the interface. The gas phase inside the bubble is a mixture of vapor and noncondensable gas, where binary diffusion between the mixture components is taken into account. The gas diffusion in the surrounding liquid is also considered. This method is applied to a simulation of a single spherical bubble collapse with heat and mass transfer across the interface in a compressible liquid. When noncondensable gas is present, it accumulates near the interface due to vapor condensation, thereby preventing further condensation. This results in a weaker bubble collapse than the case without noncondensable gas.

How do bubbles reduce the speed of sound in a bubbly liquid in a duct?
Junya Kawahara, Masao Watanabe, Kazumichi Kobayashi
Mechanical Engineering Letters, 1, 115-00464, 15-00464, 2015年12月, ［査読有り］
英語, 研究論文（学術雑誌）

低圧力環境下での高速液滴衝突により発生する液膜流れ
加藤昌也, 渡部正夫, 小林一道, 真田俊之
混相流, 28, 5, 531, 536, 2015年03月, ［査読有り］, ［招待有り］
日本語, 研究論文（学術雑誌）

Numerical study of light propagation in agricultural products for non-destructive assessment of food quality 1
Kiyohito Hattori, Hiroyuki Fujii, Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 9792, SPIE, 2015年, ［査読有り］
英語, 研究論文（国際会議プロシーディングス）, An accurate determination of optical properties of agricultural products is crucial for non-destructive assessment of food quality. For the determination, light intensity is measured at the surface of the product
then, inverse analysis is employed based on a light propagation model such as the radiative transfer equation (RTE). The inverse analysis requires high computational loads because the light intensity is numerically calculated using the model every time the optical properties are changed. For the calculation, we propose an efficient technique by combining a numerical solution with an analytical solution of the RTE, and investigate the validity of the technique in a two-dimensional homogeneous circular medium which is regarded as a light propagation model with optical properties of kiwifruit. The proposed technique can provide accurate results of the light intensity in change of the optical properties, and the accuracy is less dependent on the boundary conditions and source-detector angles. In addition, the technique can reduce computation time compared with that for numerical calculation of the RTE. These results indicate usefulness of the proposed technique for the inverse analysis.

Observation of Water-Droplet Impacts with Velocities of O(10 m/s) and Subsequent Flow Field
Y. Tatekura, T. Fujikawa, Y. Jinbo, T. Sanada, K. Kobayashi, M. Watanabe
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY, 4, 9, N117, N123, ELECTROCHEMICAL SOC INC, 2015年, ［査読有り］
英語, 研究論文（学術雑誌）, A two-fluid spray cleaning technique has been gaining popularity as a cleaning process in the semiconductor industry. The most essential physical process in this technique is the impact of droplets with a velocity of O(10 m/s) on a solid surface. This study aims to experimentally and numerically investigate water-droplet impacts with velocities of up to 50 m/s and their subsequent flow fields, especially the gas flow field in the strictly limited area in the vicinity of the contact line. First, we experimentally evaluated the velocity of the splash and numerically calculated the gas velocities. Comparison of these velocities supported our assumption that the maximum gas velocity may be on approximately the same order as the velocity of the splash. Therefore, we concluded that the gas velocity field of the order of 500 m/s indeed develops at the impact of droplet with a velocity of the order of 50 m/s. Moreover, we determined that the gas pressure was of the order of 1.0 MPa by numerical analysis. Such a high pressure leads to shock wave propagation, which can contribute to the cleaning process in semiconductor production. (C) 2015 The Electrochemical Society. All rights reserved.

Method of determining kinetic boundary conditions in net evaporation/condensation
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
PHYSICS OF FLUIDS, 26, 7, 072003, AMER INST PHYSICS, 2014年07月, ［査読有り］
英語, 研究論文（学術雑誌）, The aim of the present study is to develop the method of determining the kinetic boundary condition (KBC) at a vapor-liquid interface in net evaporation/condensation. We proposed a novel method for determining the KBC by combining the numerical simulations of the mean field kinetic theory and the molecular gas dynamics. The method was evaluated on steady vapor flow between two liquid slabs at different temperatures. A uniform net mass flux in the vapor phase induced by net evaporation and condensation is obtained from the numerical simulation of the mean field kinetic theory for both vapor and liquid phases. The KBC was specified by using the uniform net mass flux, and the numerical simulation of the molecular gas dynamics was conducted for the vapor phase. Comparing the macroscopic variables in the vapor phase obtained from both numerical simulations, we can validate the KBC whether the appropriate solutions are obtained. Moreover, the evaporation and condensation coefficients were estimated uniquely. The results showed that the condensation and evaporation coefficients were identical and constant in net evaporation. On the other hand, in net condensation, the condensation coefficient increased with the collision molecular mass flux. We also presented the applicable limit of the KBC which is assumed to be the isotropic Gaussian distribution at the liquid temperature. From these results, the KBCs in net evaporation and condensation, which enable the exact macroscopic variables to be determined, were proposed. (C) 2014 AIP Publishing LLC.

常温でのメタノールの蒸発係数と凝縮係数及び気体論境界条件の検討
小林一道, 毛利信吾, 渡邉優介, 渡部正夫, 藤川重雄
Netsu Bussei, 27, 1, 9, 14, JAPAN SOCIETY OF THERMOPHYSICAL PROPERTIES, 2013年01月, ［査読有り］
日本語, 研究論文（学術雑誌）, 衝撃波管内で蒸気中を伝播する衝撃波が管端で反射した際に管端面で生ずる膜状凝縮について，液膜の成長速度を光多重反射干渉計で測定し，測定結果を分子気体力学で解析することにより，常温でのメタノールの蒸発係数及び凝縮係数を決定した．測定は気液界面での蒸気の非平衡度σ/ρ*が1≤σ/ρ*<1.3の範囲でなされた．その結果，凝縮係数は気液界面での蒸気の非平衡度が1≤σ/ρ*<1.05の領域では蒸発係数（＝0.86）とほぼ同じ値をとること，σ/ρ*＞1.05の領域では非平衡度の増大とともに蒸発係数よりも小さくなっていくこと，さらに著者らが用いてきた気体論境界条件はσ/ρ*<1.05の領域で有効であることを明らかにした．

蒸発・凝縮をともなう非線形共鳴音波
稲葉匡司, 矢野猛, 小林一道, 渡部正夫
ながれ, 31, 6, 487, 490, 日本流体力学会, 2012年12月25日
日本語

水蒸気と水の混合噴流による表面薄膜はく離（アルミニウム蒸着膜のはく離特性と表面温度変化の影響）
真田俊之, 橋本健太郎, 林田充司, 小林 一道, 渡部正夫
混相流, 26, 2, 172, 177, THE JAPANESE SOCIETY FOR MULTIPHASE FLOW, 2012年, ［査読有り］
日本語, 研究論文（学術雑誌）, We have been developing a novel surface cleaning technique using steam and water mixed spray. Our technique shows great efficiency in removing thin surface film such as photo-resist film. However, the film-removal mechanism has not been clarified yet. One possible film-removal mechanism is the local heat expansion due to the difference of coefficients of linear expansion between film and substrate. In this study, we studied the removal characteristics of deposited aluminum film on a glass surface by spraying steam-water or air-water mixed spray. The surface temperature changes caused by the spray were carefully measured. We found that the steam and water mixed spray that increases the surface temperature can remove the film while the air and water mixed spray cannot. These results indicate that the difference of coefficients of linear expansion between film and substrate may not be the dominant factor in the film removal by the steam and water mixed spray.

固体表面に衝突する単一液滴変形過程の観察 （液滴物性，対象物表面粗さ及び周囲気体圧力の影響）
櫻井泰貴, 小林一道, 藤川俊秀, 真田俊之, 渡部正夫
混相流, 26, 2, 164, 171, 2012年, ［査読有り］
日本語, 研究論文（学術雑誌）

High-Speed Droplet Impact as an Elementary Process of Physical Cleaning
Toshihide Fujikawa, Yuuki Tatekura, Kazumichi Kobayashi, Toshiyuki Sanada, Atsushi Hayashida, Masao Watanabe
ECS Transactions, 41, 5, 67, 74, The Electrochemical Society, 2011年10月04日, ［査読有り］
英語, 研究論文（学術雑誌）, In the steam-water mixed spray-cleaning technique, droplet impact on the solid surface is the one of the primarily important physical processes. We experimentally studied a droplet impact on a solid plate that moves with a speed ranging from 1 to 50 m/s using high-speed video camera. We observed that high-speed liquid film flows radially outward along the surface just after the impact. In addition, we also observed that liquid turns into corona splash in the cases of higher impact velocities. These flows with large velocities can generate huge shear stress on the solid surface, which may contribute to cleaning. Furthermore, we numerically studied the velocity field development and found that gas flow also spreads obliquely upward. The obliquely upward flow field may also contribute in advecting removed particles or stripped resists away from the original place.

Shock wave–bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method
Kazumichi Kobayashi, Tetsuya Kodama, Hiroyuki Takahira
Physics in Medicine and Biology, 56, 19, 6421, 6440, IOP PUBLISHING LTD, 2011年10月, ［査読有り］
英語, 研究論文（学術雑誌）, Archive(HUSCAP)-> http://hdl.handle.net/2115/47143

圧力変動下でのリン脂質に覆われたマイクロバブルの挙動
田中佑樹, 小林一道, 高比良裕之
混相流, 24, 5, 559, 566, 日本混相流学会, 2011年03月, ［査読有り］, ［招待有り］
日本語, 研究論文（学術雑誌）

液体中での衝撃波と気泡との干渉問題へのマルチグリッドGhost Fluid法の適用
小林一道, 神保佳典, 高比良裕之
日本機械学会論文集 (B編), 77, 773, 20, 32, 2011年01月, ［査読有り］
日本語

浮体下での気泡力学に関する境界要素解析(第2報, 球形気泡モデルを用いた近似解法)
神保佳典, 高比良裕之, 小林一道, 安田章宏
日本機械学会論文集 (Ｂ編), 76, 762, 230, 238, Japan Society of Mechanical Engineers, 2010年, ［査読有り］
日本語, 研究論文（学術雑誌）, A fast simulation method is proposed for underwater explosion. In the method, the motion of a bubble generated by the underwater explosion is modeled with a point source and a doublet
the source and doublet represent the radial motion and translational of the bubble, respectively. The bubble motions are solved coupling with the motions of free surface and a floating body by using the boundary element method (BEM). The growth and collapse of a bubble under a floating body is simulated with the present method. It is shown that the present results are in qualitative agreement with those obtained from the BEM without the bubble model in which the interfacial motion of a bubble is solved directly with the BEM. The present simulation is found to be about six times faster than the BEM simulation without the bubble model.

浮体下での気泡力学に関する境界要素解析(第1報，線形要素を用いた三次元境界要素法による数値計算)
神保佳典, 高比良裕之, 小林一道, 安田章宏
日本機械学会論文集 (Ｂ編), 76, 762, 219, 229, Japan Society of Mechanical Engineers, 2010年, ［査読有り］
日本語, 研究論文（学術雑誌）, The growth and collapse of a bubble under a floating body are simulated by using the boundary element method with linear elements to predict the damage of ship bodies induced by underwater explosion. The three-dimensional deformation of the bubble, the translation and rotation of the floating body, and the motion of water surface are taken into account in the simulation. It is shown that the bubble deforms three-dimensionally, and the liquid jet threads the bubble due to the interactions among the bubble, the floating body, and the water surface
the directions of the bubble translation and the liquid jet depend on the initial location of the bubble. The Kelvin impulse is found to be useful in evaluating the translational motion of the bubble. Also, the horizontal translational motion of the bubble is much dependent on the rotational motion of a floating body
when the moment of inertia of the floating body is small, the largest horizontal translation is realized between the axis of flotation and the edge of the floating body. It is also shown that there exists an initial horizontal bubble location where the moment of force acting on the floating body has the maximum value.

An optical interferometer for measurement of the condensation rate of a vapor in a vapor-liquid nonequilibrium state　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Shigeo Fujikawa
Handbook of Interferometers: Research, Technology and Applications, 605, 614, Nova Science Publishers, Inc., 2009年11月05日
英語, 論文集(書籍)内論文, This chapter provides a review on an optical interferometer for fine measurement of the condensation rate of a vapor on the endwall surface of the vapor-filled low-pressure section of a shock tube. The interferometer, the original idea of which was proposed by Fujikawa et al. [1, 2], is an optical system composed of a liquid film formed on the endwall surface, the transparent endwall made of quartz glass, and physical and reference light beams. The reference beam is used to eliminate systematic noises from the physical one. Measurements of the time evolution in thickness of the liquid film for water or methanol demonstrate that it is obtained with a sufficient accuracy. From the time evolution and the theoretical counterpart based on the Gaussian-BGK Boltzmann equation, values of the condensation coefficient, an unknown parameter involved in the kinetic boundary condition at the vapor-liquid interface, are determined for water and methanol.

Direct numerical simulations of interaction of strong shock waves with nonspherical gas bubbles near glass boundaries in mercury
Hiroyuki Takahira, Kazumichi Kobayashi, Takahi Matsuno
International Journal of Emerging Multidisciplinary Fluid Sciences, 1, 2, 85, 99, 2009年06月01日, ［査読有り］
英語, 研究論文（学術雑誌）, The present study is concerned with the material damage of the liquid-mercury target systems induced by bubble collapse. The interaction of an incident strong shock wave with an initially spherical bubble near a glass wall in mercury is simulated using an improved Ghost Fluid Method (GFM), in which Riemann solutions are utilized to correct the values at boundary nodes. The mercury and glass are evaluated by using the equation of state for stiffened gas. The axi-symmetric motions of three phases for air, mercury, and glass are solved directly coupling the GFM with the level set method. The interaction of the shock wave with the bubble leads to the bubble deformation and the formation of liquid-jet during the collapse. The strong shock waves are generated in the mercury not only when the bubble rebounds but also when the liquid-jet impacts downstream surface of the bubble. It is shown that the impact of the shock waves on the glass wall leads to the formation of depression of the glass surface
the toroidal bubble formed after the impact of liquid-jet penetrates into the depression. The present results for the axi-symmetric bubble collapse are compared with those for the two-dimensional cylindrical bubble collapse. The stronger shock waves are generated when the axi-symmetric bubble collapses, which results in the higher impulsive pressure at the glass wall and the deeper depression of the glass surface.

Condensation coefficient of water in a weak condensation state
Kazumichi Kobayashi, Shunsuke Watanabe, Daigo Yamano, Takeru Yano, Shigeo Fujikawa
FLUID DYNAMICS RESEARCH, 40, 7-8, 585, 596, IOP PUBLISHING LTD, 2008年07月, ［査読有り］
英語, 研究論文（学術雑誌）, The condensation coefficient of water at a vapor-liquid interface is determined by combining shock tube experiments and numerical simulations of the Gaussian-BGK Boltzmann equation. The time evolution in thickness of a liquid film, which is formed on the shock tube endwall behind the shock wave reflected at the endwall, is measured with an optical interferometer consisting of the physical beam and the reference one. The reference beam is utilized to eliminate systematic noises from the physical beam. The growth rate of the film is evaluated from the measured time evolution and it is incorporated into the kinetic boundary condition for the Boltzmann equation. From a numerical simulation using the boundary condition, the condensation coefficient of water is uniquely deduced. The results show that, in a condition of weak condensation near a vapor-liquid equilibrium state, the condensation coefficient of water is almost equal to the evaporation coefficient estimated by molecular dynamics simulations near a vapor-liquid equilibrium state and it decreases as the system becomes a nonequilibrium state. The condensation coefficient of water is nearly identical with that of methanol [Mikami, S., Kobayashi, K., Ota, T., Fujikawa, S., Yano, T., Ichijo, M., 2006. Molecular gas dynamics approaches to interfacial phenomena accompanied with condensation. Exp. Therm. Fluid Sci. 30, 795-800]. (c) 2008 The Japan Society of Fluid Mechanics and Elsevier B.V. All rights reserved.

Molecular gas dynamics approaches to interfacial phenomena accompanied with condensation
S. Mikami, K. Kobayashi, T. Ota, S. Fujikawa, T. Yano, M. Ichijo
EXPERIMENTAL THERMAL AND FLUID SCIENCE, 30, 8, 795, 800, ELSEVIER SCIENCE INC, 2006年08月, ［査読有り］
英語, 研究論文（学術雑誌）, This paper deals with the condensation coefficient of methanol, which is evaluated from a condensation rate at the vapor-liquid interface. Film condensation is induced on the endwall of a vapor-filled shock tube, when a shock wave is reflected at the endwall and the vapor becomes supersaturated there. The liquid film grows with the lapse of time. The evolution in time of the liquid film thickness is measured by an optical interferometer with a high accuracy, and thereby the net condensation mass flux at the interface is obtained. The mass flux is incorporated into the kinetic boundary condition (KBC) at the interface for the Gaussian-BGK Boltzmann equation. Such a treatment of the boundary condition makes it possible to formally eliminate the evaporation and condensation coefficients in KBC and to obtain the unique numerical solution of the vapor-liquid system. In this way, the instantaneous condensation coefficient is accurately evaluated from the conformity with experiment and numerical solution. It is found that the values of condensation coefficient are, near vapor-liquid equilibrium states, close to those evaluated by molecular dynamics simulations. (C) 2006 Published by Elsevier Inc.

衝撃波管管端でのメタノール蒸気の凝縮過程に関する分子気体力学解析
日本機械学会論文集
矢野猛, 小林一道, 藤川重雄, 71, 702, 428, 435, Japan Society of Mechanical Engineers, 2005年, ［査読有り］
日本語, 研究論文（学術雑誌）, Film condensation phenomenon of methanol vapor at the endwall of a shock tube behind a reflected shock wave is studied by combining a shock tube experiment with a numerical analysis based on molecular gas dynamics. The present method of analysis utilizes the Gaussian-BGK Boltzmann equation, which is applicable to a strong condensation of polyatomic gases, and thereby some restrictions included in our previous method of analysis are removed. The result shows that the condensation cofficient is nearly unity when the ratio of the vapor pressure to the saturated vapor pressure at the interface is close to unity, and it decreases with the increase of the pressure ratio. Furthermore, the relations between the vapor condition and the condensation coefficient are extended to the second order so that it may contain the effect of moderately strong condensation and that of polyatomic molecules.

Molecular gas dynamics applied to phase change processes at a vapor-liquid interface: shock-tube experiment and MGD computation for methanol
S Fujikawa, T Yano, K Kobayashi, K Iwanami, M Ichijo
EXPERIMENTS IN FLUIDS, 37, 1, 80, 86, SPRINGER, 2004年07月, ［査読有り］
英語, 研究論文（学術雑誌）, This paper deals with a molecular gas-dynamics method applied to the accurate determination of the condensation coefficient of methanol vapor. The method consisted of an experiment using a shock tube and computations using a molecular gas-dynamics equation. The experiments were performed in such situations where the shift from a vapor-liquid equilibrium state to a nonequilibrium one is realized by a shock wave in a scale of molecular mean free time of vapor molecules. The temporal evolution in thickness of a liquid film formed on the shock-tube endwall behind a reflected shock wave is measured by an optical interferometer. By comparing the measured liquid-film thickness with numerical solutions for a polyatomic version of the Gaussian-BGK model of the Boltzmann equation, the condensation coefficient of methanol vapor is accurately determined in vapor-liquid nonequilibrium states. As a result, it is clear that the condensation coefficient is just unity very near to an equilibrium state, but is smaller far from the equilibrium state.

Numerical study of condensation of a polyatomic vapor by a shock wave based on the kinetic theory of gases
Takeru Yano, Kazumichi Kobayashi, Shigeo Fujikawa
Proceedings of the ASME/JSME Joint Fluids Engineering Conference, 1, 1457, 1462, American Society of Mechanical Engineers, 2003年
英語, 研究論文（国際会議プロシーディングス）, A semi-infinite expanse of a polyatomic vapor bounded by its condensed phase is considered. The condensed phase is a thin liquid film on a solid wall of finite thickness. An incident shock wave is reflected at the liquid film, and thereby the pressure behind the reflected shock exceeds the saturated pressure. Then, the vapor begins to condense onto the surface of the liquid film. We present the results of numerical study of the behavior of vapor and the growth rate of liquid film based on the kinetic theory, the Gaussian-BGK model of the Boltzmann equation with a kinetic boundary condition of a mixed type including the condensation coefficient. It is shown that both the behavior of vapor and the growth rate of liquid film are considerably affected by values of the condensation coefficient. The numerical results are also compared with those by a previous theory.

Numerical Modelling of Initial Photoacoustic Pressure in Colloidal Suspensions for Photoacoustic Imaging
藤井 宏之, 青木 俊晃, 井上 優輝, 寺林 伊織, 小林 一道, 渡部 正夫, Technical digest of 26th Microoptics Conference (MOC2021), PO-11, 164, 165, 2021年09月, ［査読有り］
日本応用物理学会, 英語

Finite element investigation of light propagationin the human neck using the time-dependent radiative transfer theory
遠藤 茂樹, 藤井 宏之, 小林 一道, 渡部 正夫, Proceeding of the 7th Asian NIR symposium (ANS2020), 2020, NRT-0008, 60, 61, 2020年02月, ［査読有り］
英語

Numerical study on light propagation in a white bread loaf
藤井 宏之, 西村 吾朗, 遠藤 茂樹, 野村 航希, 小林 一道, 渡部 正夫, Proceeding of the 7th Asian NIR symposium (ANS2020), 2020, AFI-0007, 14, 15, 2020年02月, ［査読有り］, ［国際誌］
英語

Numerical treatment of highly forward scattering on radiative transfer using the delta-M approximation and Galerkin quadrature method
藤井 宏之, 千葉 豪, 山田 幸生, 星 詳子, 小林 一道, 渡部 正夫, Proceedings of the 9th International Symposium on Radiative Transfer, RAD-19, SM05, 261, 268, 2019年09月, ［査読有り］
英語

Numerical errors of light propagation in the two-dimensional human neck model using the time-dependent radiative transfer equation with renormalized phase functions
藤井 宏之, 山田 幸生, 星 詳子, 小林 一道, 渡部 正夫, AIP Conference Proceedings (ICNAAM2018), 2116, 450037, 1, 4, 2019年07月, ［査読有り］
英語

Finite element investigation of a void region on light propagation in scattering media using the radiative transfer equation
田林 孝介, 藤井 宏之, 小林 一道, 渡部 正夫, AIP Conference Proceedings (ICNAAM2018), 2116, 450052, 1, 4, 2019年07月, ［査読有り］
英語

Light propagation models of the human neck for photoacoustic imaging of thyroid cancer
田林 孝介, 藤井 宏之, 大川 晋平, 小林 一道, 山田 幸生, 星 詳子, 渡部 正夫, CMBE Proceedings (6th International Conference on Computational & Mathematical Biomedical Engineering), A5, 161, 164, 2019年05月, ［査読有り］
英語

エタノール液滴のスプラッシュ発生に及ぼす蒸気の凝縮効果
澤井 冴, 渡部 正夫, 小林 一道, 藤井 宏之, 真田 俊之, 流体工学部門講演会講演論文集, 2018, OS2-17, 2019年05月, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

単一液滴衝突時に取り込まれる空気膜の観察
遠藤 理一郎, 渡部 正夫, 小林 一道, 藤井 宏之, 流体工学部門講演会講演論文集, 2018, OS2-5, 2019年05月, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

Correction to: Influence of liquid–solid intermolecular force on levitation of impacting nanodroplet　　　　　　　　　　　　　　　
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe, Heat and Mass Transfer, 55, 4, 1005, 1005, 2019年04月, ［査読有り］, ［筆頭著者, 責任著者］
英語

Molecular Dynamics Study on Influence of Liquid-solid Intermolecular Force on Levitating Mechanism of Impacting Nanodroplet on Heated Wall　　　　　　　　　　　　　　　
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe, Surface Wettability Effects on Phase Change Phenomena(SWEP), 2019年, ［査読有り］

Numerical study of light scattering in the human neck for diagnosis of thyroid cancers by optical tomography
藤井 宏之, 山田 幸生, 星 詳子, 小林 一道, 渡部 正夫, Extended abstract of the 12th CME International Conference, OS12, 2, 2018年
英語, 研究発表ペーパー・要旨（国際会議）

分子動力学法を用いた高温壁へ衝突するナノ液滴の浮遊メカニズム解析
田部 広風海, 小林 一道, 矢口 久雄, 藤井 宏之, 渡部 正夫, マイクロ・ナノ工学シンポジウム, 2018.9, 30pm4PN16, 2018年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

高温壁へ衝突する液滴の浮遊メカニズムに関する分子動力学解析
田部 広風海, 小林 一道, 矢口 久雄, 藤井 宏之, 渡部 正夫, 流体工学部門講演会講演論文集, 2018, OS2-1, 2018年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

粘弾性乳液滴と固体表面の高速衝突の観察
伊藤 一樹, 芦田 拓, 渡部 正夫, 小林 一道, 藤井 宏之, 吉岡 孝一郎, 大井 航, 髙野 真, 流体工学部門講演会講演論文集, 2018, OS2-23, 2018年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

低圧環境下における高速液滴衝突直後に発生するsplashの観察
芦田 拓, 渡部 正夫, 小林 一道, 藤井 宏之, 真田 俊之, 流体工学部門講演会講演論文集, 2018, OS2-9, 2018年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

Influence of surface roughness of high temperature wall on levitation of impacting droplet based on molecular dynamics simulation　　　　　　　　　　　　　　　
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe, Surface Wettability Effects on Phase Change Phenomena (SWEP) workshop, 2018年, ［査読有り］
英語

Numerical investigation of light and pressure propagation in biological tissue for model-based photoacoustic tomography　　　　　　　　　　　　　　　
田林 孝介, 藤井 宏之, 小林 一道, 渡部 正夫, Extended Abstracts of The 9th JSME-KSME Thermal and Fluids Engineering Conference, TFEC9-1526, 1, 4, 2017年10月, ［査読有り］
英語

蒸発・凝縮を伴う球形気泡の崩壊現象における凝縮係数の影響 (第30回数値流体力学シンポジウム特集) -- (特集 注目研究in CFD30)
森川 昌太郎, 立藏 祐樹, 小林 一道, 藤井 宏之, 渡部 正夫, 佐々木 浩一, ながれ : 日本流体力学会誌 = Nagare : journal of Japan Society of Fluid Mechanics, 36, 2, 105, 108, 2017年04月
日本流体力学会, 日本語

Numerical Calculation Of Time-resolved Light Reflectance From Biological Tissue Using The Radiative Transfer Equation
Hiroyuki Fujii, Yukio Yamada, Yoko Hoshi, Kazumichi Kobayashi, Masao Watanabe, Extended abstract of The International Conference on Mathematics in (bio)Chemical Kinetics and Engineering (MaCKiE) 2017, 2017年
英語, 研究発表ペーパー・要旨（国際会議）

拡散光による甲状腺腫瘍診断のためのヒト頸部内における光伝播の数値解析
藤井 宏之, 山田 幸生, 星 詳子, 小林 一道, 渡部 正夫, 第３３回近赤外フォーラム 講演論文集, I, 07, 2017年
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

Molecular Dynamics Study of Droplet Impact on High-Temperature Wall　　　　　　　　　　　　　　　
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe, The 7th East Asia Mechanical and Aerospace Engineering Workshop, 2017年, ［査読有り］
英語

Molecular Dynamics Simulation of the Role of the Wettability in the Droplet Impact on a High-temperature Wall　　　　　　　　　　　　　　　
Hirofumi Tabe, Kazumichi Kobayashi, Hisao Yaguchi, Hiroyuki Fujii, Masao Watanabe, Extended Abstracts of the 9th JSME-KSME Thermal and Fluids Engineering Conference, TFEC9-1492, 2017年, ［査読有り］
英語

研究室紹介 北海道大学 大学院工学研究院 機械宇宙工学部門 流体力学研究室
渡部 正夫, 小林 一道, 藤井 宏之, 混相流 = Japanese journal of multiphase flow, 30, 4, 408, 411, 2016年12月
日本混相流学会, 日本語

Near-infrared optical properties of white bread using the light propagation model
藤井 宏之, 西村 吾朗, 服部 聖仁, 小林 一道, 渡部 正夫, Proceeding of the fifth Asian NIR symposium (ANS2016), 2016, P-86, 288, 289, 2016年, ［査読有り］
英語

Quantitative method to determine the optical properties of melons by the photon diffusion equation
服部 聖仁, 藤井 宏之, 西村 吾朗, 小林 一道, 渡部 正夫, Proceeding of the fifth Asian NIR symposium (ANS2016), 2016, O-6, 72, 73, 2016年, ［査読有り］
英語

蒸気と気体で満たされた球形気泡の収縮・膨張運動に関する分子気体力学解析
永山 貴大, 今 美沙紀, 小林 一道, 渡部 正夫, 藤井 宏之, 高比良 裕之, 流体工学部門講演会講演論文集, 2016, 0727, 2016年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

Numerical Study of Photon Migration in the Presence of a Void Region using the radiative Transfer and Diffusion Equations
Erina Miyakawa, Hiroyuki Fujii, Kiyohito Hattori, Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe, Proceedings of the International Conference of Computational Methods in Sciences and Engineering 2016 (ICCMSE-2016), 1790, 050003, 2016年, ［査読有り］
Diffuse optical tomography (DOT), which is still under development, has a potential to enable non-invasive diagnoses of thyroid cancers in the human neck using the near-infrared light. This modality needs a photon migration model because scattered light is used. There are two types of photon migration models: the radiative transport equation (RTE) and diffusion equation (DE). The RTE can describe photon migration in the human neck with accuracy, while the DE enables an efficient calculation. For developing the accurate and efficient model of photon migration, it is crucial to investigate a condition where the DE holds in a scattering medium including a void region under the refractive-index mismatch at the void boundary because the human neck has a trachea (void region) and the refractive indices are different between the human neck and trachea. Hence, in this paper, we compare photon migration using the RTE with that using the DE in the medium. The numerical results show that the DE is valid under the refractive-index match at the void boundary even though the void region is near the source and detector positions. Under the refractive-index mismatch at the boundary, the numerical results using the DE disagree with those using the RTE when the void region is near the source and detector positions. This is probably because the anisotropy of the light scattering remains around the void boundary., AMER INST PHYSICS, 英語

Molecular Dynamics Simulation on Kinetic Boundary Conditions of Gas-Vapor Binary Mixture
Kazumichi Kobayashi, Kiyofumi Sasaki, Misaki Kon, Hiroyuki Fujii, Masao Watanabe, 30TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS (RGD 30), 1786, 110002, 2016年, ［査読有り］
The aim of this study is to construct the kinetic boundary condition for Ar-Ne binary mixture in equilibrium using molecular dynamics (MD) simulations. The temperature of the MD simulation system is 85 K; Ar molecules behave as condensable gas (vapor), and Ne molecules behave as non-condensable gas (gas). In this simulation, we utilize the two-boundary method improved by our previous study to investigate behaviors of Ar and Ne molecules at the interface. From the results, we can obtain the molecular mass fluxes at the interface, and evaluate the values of evaporation and condensation coefficients of Ar (vapor) and Ne (gas) molecules., AMER INST PHYSICS, 英語

Molecular Simulation of Evaporation Mass Flux during Net Evaporation/Condensation
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe, 30TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS (RGD 30), 1786, 110001, 2016年, ［査読有り］
To examine the transport phenomena in a vaporliquid two-phase system attributed to the phase change, a proper specification of the mass flux at a vaporliquid interface is crucial. Since the mass flux induced by the phase change originates from the motion of molecules in the vicinity of the vaporliquid interface, a continuum description such as the fluid dynamic based approach is inappropriate. An essential way to obtain this mass flux is the analysis of the Boltzmann equation with a certain boundary condition, that is, the kinetic boundary condition. In this study, we examined the definition and the estimation procedure of the evaporation coefficient, which is included in the kinetic boundary condition, at the vaporliquid interface with phase change, especially at higher temperature for hard-sphere molecules. As the result, we confirmed that a conventional definition of the evaporation coefficient is accurate even if liquid temperature is higher. Moreover, we also confirmed that the evaporation coefficient is only the function of liquid temperature by counting the number of molecules passing through the two boundaries which are placed near the vaporliquid interface., AMER INST PHYSICS, 英語

J0540204 Enskog-Vlasov方程式による液膜と壁に挟まれた気体のせん断流れに関する数値計算
今 美沙紀, 小林 一道, 渡部 正夫, 年次大会 : Mechanical Engineering Congress, Japan, 2015, "J0540204, 1"-"J0540204-3", 2015年09月13日
The aim of this study is to investigate the relation between the slip velocity at the gas-liquid interface and the rarefaction. We carried out the numerical simulation of the steady shear flow between the liquid slab and the solid wall with changing Knudsen number based on mean field kinetic theory. The simulation results showed that the slip velocity at the gas-liquid interface increases with the increase of Knudsen number. On the other hand, the slip velocity at the gas-solid interface is smaller than that at the gas-liquid interface in all cases of Knudsen number., 一般社団法人日本機械学会, 日本語

J0540301 分子気体力学に基づく気液界面の境界条件を適用した相変化を伴う気泡運動を表す数理モデルの数値計算
森川 昌太郎, 神保 佳典, 立藏 祐樹, 小林 一道, 渡部 正夫, 年次大会 : Mechanical Engineering Congress, Japan, 2015, "J0540301, 1"-"J0540301-5", 2015年09月13日
The collapse and rebound of a single spherical bubble with phase changes at the vapor-iquid interface are fundamental physical phenomena in the fields of industry and medicine. In this study, we propose a mathematical model of describing the dynamics of a spherical vapor bubble with phase changes (evaporation and condensation) at the vapor-liquid interface. To deal with evaporation and condensation phenomena at the interface precisely, we utilize the boundary condition of the interface derived from the molecular gas dynamics analysis. The calculation results of the mathematical model show that the maximum pressure inside a bubble due to the bubble collapse with phase changes becomes higher than that of the bubble collapse without phase changes., 一般社団法人日本機械学会, 日本語

22aAK-12 気液界面における速度分布関数の非平衡性が蒸気の流れに与える影響
今 美沙紀, 小林 一道, 渡部 正夫, 日本物理学会講演概要集, 70, 2975, 2975, 2015年
一般社団法人日本物理学会, 日本語

反射衝撃波によって誘起される非凝縮性気体を伴う蒸気の凝縮現象に関する分子気体力学に基づく数値計算
永山 貴大, 藤井 宏之, 小林 一道, 渡部 正夫, 日本機械学会年次大会, 2015, J0540205, 2015年
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

シリンジを用いた高速液滴射出装置の開発および液滴衝突の観察
片岡 豊, 堀 優作, 渡部 正夫, 小林 一道, 藤井 宏之, 日本機械学会年次大会, 2015, G0500203, 2015年
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

異なる境界条件を課した生体モデルにおける光伝播の数値解析
服部 聖仁, 藤井 宏之, 小林 一道, 渡部 正夫, 日本機械学会年次大会, 2015, J2410103, 2015年
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

固体壁面の濡れ性が液滴衝突により発生する流れの進展挙動に与える影響の観察
山口 陽平, 渡部 正夫, 小林 一道, 藤井 宏之, 真田 俊之, 流体工学部門講演会講演論文集, 2015, 317, 2015年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

低圧環境下での高速液滴衝突によるSplash発生の観察
東 稜, 渡部 正夫, 小林 一道, 藤井 宏之, 流体工学部門講演会講演論文集, 2015, 318, 2015年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

シリンジを用いた高速微細液滴射出装置の開発
堀 優作, 片岡 豊, 渡部 正夫, 小林 一道, 藤井 宏之, 流体工学部門講演会講演論文集, 2015, 319, 2015年, ［査読有り］
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

エタノール液滴と固体壁の衝突現象に周囲気体種が及ぼす影響
磯野 俊悠, 渡部 正夫, 小林 一道, 藤井 宏之, 日本機械学会年次大会, 2015, G0500202, 2015年
日本語, 研究発表ペーパー・要旨（全国大会，その他学術会議）

Numerical study of light propagation in agricultural products for non-destructive assessment of food quality
Kiyohito Hattori, Hiroyuki Fujii, Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe, BIOPHOTONICS JAPAN 2015, 9792, 97921A, 2015年, ［査読有り］
An accurate determination of optical properties of agricultural products is crucial for non-destructive assessment of food quality. For the determination, light intensity is measured at the surface of the product; then, inverse analysis is employed based on a light propagation model such as the radiative transfer equation (RTE). The inverse analysis requires high computational loads because the light intensity is numerically calculated using the model every time the optical properties are changed. For the calculation, we propose an efficient technique by combining a numerical solution with an analytical solution of the RTE, and investigate the validity of the technique in a two-dimensional homogeneous circular medium which is regarded as a light propagation model with optical properties of kiwifruit. The proposed technique can provide accurate results of the light intensity in change of the optical properties, and the accuracy is less dependent on the boundary conditions and source-detector angles. In addition, the technique can reduce computation time compared with that for numerical calculation of the RTE. These results indicate usefulness of the proposed technique for the inverse analysis., SPIE-INT SOC OPTICAL ENGINEERING, 英語

気液界面での質量・運動量・エネルギーの輸送 : 分子動力学,分子気体力学,実験の融合(第5章)蒸発・凝縮の衝撃波管による実験
小林 一道, 藤川 重雄, ながれ : 日本流体力学会誌 = Nagare : journal of Japan Society of Fluid Mechanics, 33, 6, 543, 548, 2014年12月
日本流体力学会, 日本語

学会だより 日本混相流学会 混相流シンポジウム2014報告
村井 祐一, 小林 一道, 混相流, 28, 4, 483, 486, 2014年12月
日本混相流学会, 日本語

第4章 蒸発・凝縮への分子気体力学の適用(<連載>気液界面での質量・運動量・エネルギーの輸送-分子動力学,分子気体力学,実験の融合-)
小林 一道, 藤川 重雄, Kazumichi Kobayashi, Shigeo Fujikawa, 北海道大学大学院工学研究院, 北海道大学大学院工学研究院, Graduate School of Engineering Hokkaido University, Graduate School of Engineering Hokkaido University, ながれ : 日本流体力学会誌 = Journal of Japan Society of Fluid Mechanics, 33, 5, 453, 459, 2014年10月25日
日本流体力学会, 日本語

Molecular Dynamics Simulation on Evaporation Molecules in a Vapor-Liquid Equilibrium State
Kazumichi Kobayashi, Kazumasa Hori, Hisao Yaguchi, Masao Watanabe, PROCEEDINGS OF THE 29TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 1628, 404, 410, 2014年, ［査読有り］
By using molecular dynamics simulations of argon molecules, the present study investigates molecular evaporation and reflection in equilibrium at a vapor liquid interface, which involves the kinetic boundary condition (KBC) of the Boltzmann equation. The present method allows evaporation and reflection molecules to be selected naturally at the vapor-liquid interphase. Based on the results, we confirm that the evaporation molecules in the equilibrium state behave almost similar to spontaneous evaporation molecules (as determined by virtual vacuum evaporation simulations). Furthermore, we find that the velocity distribution of reflection molecules in the normal direction to the boundary is lower than the Maxwell distribution at the liquid temperature., AMER INST PHYSICS, 英語

Numerical Analysis of Kinetic Boundary Conditions at Net Evaporation/condensation Interfaces in Various Liquid Temperatures Based on Mean-field Kinetic Theory
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe, PROCEEDINGS OF THE 29TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 1628, 398, 403, 2014年, ［査読有り］
This study aims to investigate the liquid temperature dependency of the kinetic boundary condition at a vapor-liquid interface in net evaporation/condensation. The numerical simulations based on the mean-field kinetic theory and the molecular gas dynamics in the cases of various liquid temperatures were carried out. We focused on two important issues for the kinetic boundary condition; one is to investigate the applicable limit of the kinetic boundary condition which is assumed to be the isotropic velocity distribution at the liquid temperature and the other is to estimate the value of the condensation coefficient included in the kinetic boundary condition. The simulation results showed that the applicable limit of the isotropic velocity distribution in net evaporation/condensation practically independent from the liquid temperature. Furthermore, the condensation coefficients in net evaporation/condensation depend significantly on the liquid temperature; the condensation coefficient is constant and equal to the evaporation coefficient in net evaporation, while, in net condensation, the condensation coefficient increases with the increase of the degree of nonequilibrium., AMER INST PHYSICS, 英語

J053025 Enskog-Vlasov方程式による気液界面の気体論境界条件に関する数値シミュレーション(〔J053-02〕マイクロ・ナノスケールの熱流体現象(2))
小林 一道, 今 美沙紀, 大橋 広太郎, 渡部 正夫, 年次大会 : Mechanical Engineering Congress, Japan, 2013, "J053025, 1"-"J053025-4", 2013年09月08日
The aim of the present study is to investigate the kinetic boundary condition (KBC) at a vapor-liquid interface in net evaporation/condensation states by using the Enskog-Vlasov equation. Our target system is a steady evaporation and condensation state between two liquid slabs with different temperatures. The results show that we can realize the simulation of steady evaporation and condensation phenomena between the two-liquid slabs with different temperature. Also, the normal and tangential temperatures including the kinetic boundary condition is not only the function of molecular energy flux but also the function of molecular collision mass flux in net condensation interface., 一般社団法人日本機械学会, 日本語

J053024 アルゴン-ネオン系におけるアルゴン液体の蒸発に関する分子動力学解析(〔J053-02〕マイクロ・ナノスケールの熱流体現象(2))
堀 和雅, 矢萩 嵩人, 竹内 晉之輔, 矢口 久雄, 小林 一道, 渡部 正夫, 年次大会 : Mechanical Engineering Congress, Japan, 2013, "J053024, 1"-"J053024-5", 2013年09月08日
The aim of the present study is to establish the kinetic boundary condition of a vapor-liquid interface for argon-neon two-component systems by using the molecular dynamics simulation. Two kinds of simulations were conducted: vapor-liquid equilibrium and evaporation simulations at the liquid temperature 85 K. In this paper, we investigated the influence of mole rate of neon for the evaporation flux of argon and calculated the value of the evaporation coefficient. The results show that as the mole rate of neon increases, the evaporation coefficient of argon becomes smaller. The main factor for the decrease of evaporation coefficient is the increase of the outgoing molecular mass flux at the equilibrium states due to the increase of mole rate of neon. Further, the velocity distribution function of argon composed of the evaporating molecules deviates from the half - Maxwellian with the liquid temperature., 一般社団法人日本機械学会, 日本語

26pKJ-6 Enskog-Vlasov方程式による温度差のある二液膜を用いた非平衡蒸発・凝縮現象の数値解析(圧縮性流体・希薄気体,熱流体,電磁流体,地球・宇宙流体,領域11(統計力学,物性基礎論,応用数学,力学,流体物理))
今 美沙紀, 小林 一道, 渡部 正夫, 日本物理学会講演概要集, 68, 2, 248, 248, 2013年08月26日
一般社団法人日本物理学会, 日本語

相互作用を考慮した球形気泡離散モデルの解析 : 気泡流の音響特性 (非線形波動研究の数理, モデリングおよび応用)
川原 潤也, 小林 一道, 渡部 正夫, 数理解析研究所講究録, 1847, 10, 15, 2013年08月
京都大学, 日本語

Molecular Dynamics Study of Nano-scale Liquid-gas Interface Inspired by Fuel Cell Catalyst Layer　　　　　　　　　　　　　　　
Youngmin Kim, Hisao Yaguchi, Nobuyuki Oshima, Masao Watanabe, Kazumichi Kobayashi, ASME 2013 11th International Conference on Nanochannels, 2013年, ［査読有り］

304 洗浄用ノズル内の高速液滴噴霧流の数値解析(流体工学I)
田村 俊幸, 川原 潤也, 小林 一道, 渡部 正夫, 北海道支部講演会講演概要集, 2012, 51, 83, 84, 2012年10月20日
一般社団法人日本機械学会, 日本語

Derivation of Nonlinear Wave Equations for Ultrasound Beam in Nonuniform Bubbly Liquids
Tetsuya Kanagawa, Takeru Yano, Junya Kawahara, Kazumichi Kobayashi, Masao Watanabe, Shigeo Fujikawa, NONLINEAR ACOUSTICS: STATE-OF-THE-ART AND PERSPECTIVES (ISNA 19), 1474, 144, 147, 2012年, ［査読有り］
Weakly nonlinear propagation of diffracted ultrasound beams in a nonuniform bubbly liquid is theoretically studied based on the method of multiple scales with the set of scaling relations of some physical parameters. It is assumed that the spatial distribution of the number density of bubbles in an initial state at rest is a slowly varying function of space coordinates and the amplitude of its variation is small compared with a mean number density. As a result, a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation with dispersion and nonuniform effects for a low frequency case and a nonlinear Schrodinger (NLS) equation with dissipation, diffraction, and nonuniform effects for a high frequency case, are derived from the basic equations of bubbly flows., AMER INST PHYSICS, 英語

Resonant Gas Oscillation with Evaporation and Condensation
Masashi Inaba, Takeru Yano, Masao Watanabe, Kazumichi Kobayashi, Shigeo Fujikawa, NONLINEAR ACOUSTICS: STATE-OF-THE-ART AND PERSPECTIVES (ISNA 19), 1474, 80, 83, 2012年
Resonant gas oscillation in a closed tube bounded by an oscillating plate and a vapor-liquid interface is theoretically analyzed by applying the asymptotic theory to the ES-BGK Boltzmann equation for the case of M-2 similar or equal to Kn << 1 and a small evaporation coefficient alpha = O(Kn), where M and Kn are the typical Mach number and the Knudsen number, respectively. As a result, we derive a nonlinear integro-differential equation for determining the wave profile with the evaporation and condensation in the form including alpha., AMER INST PHYSICS, 英語

気液界面で蒸発・凝縮を伴う流動現象に関する分子論的アプローチ
小林 一道, 公益社団法人応用物理学会界面ナノ電子化学研究会NICE : 講演集, 11, 21, 26, 2012年
応用物理学会, 日本語

Nonlinear Resonant Gas Oscillation Accompanied with Evaporation and Condensation
Masashi Inaba, Takeru Yano, Kazumichi Kobayashi, Masao Watanabe, 28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 2012, VOLS. 1 AND 2, 1501, 53, 58, 2012年, ［査読有り］
Resonant gas oscillation in a closed tube bounded by an oscillating plate and a vapor-liquid interface is theoretically analyzed by applying the asymptotic theory to the ES-BGK Boltzmann equation for the case of M-P similar to Kn << 1 and a small evaporation coefficient alpha = O(root Kn), where M-P and Kn are the Mach number of the plate and the Knudsen number, respectively. As a result, we derive a nonlinear integro-differential equation for determining the wave profile with the evaporation and condensation including alpha. We numerically solve the integro-differential equation with the method of Fourier series, and obtain a parameter plane for shock formation conditions and also the prediction of critical condition for shock formation., AMER INST PHYSICS, 英語

Numerical Analysis of Vapor-Liquid Two-Phase System Based on the Enskog-Vlasov Equation
Kazumichi Kobayashi, Kotaro Ohashi, Masao Watanabe, 28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 2012, VOLS. 1 AND 2, 1501, 1145, 1151, 2012年, ［査読有り］
In this study, equilibrium and nonequilibrium numerical simulations for vapor-liquid two-phase systems were performed by using the Enskog-Vlasov equation. The kinetic boundary condition (KBC) at the interface was investigated. The simulation results showed that at a low or slightly high liquid temperature, the velocity distribution of the KBC obtained by our simulation is anisotropic Gaussian; this result agrees qualitatively with the results of the MD simulation performed by Ishiyama et al. (PRL, 2005). Also, the nonequilibrium nature of KBC becomes larger with the increase of liquid temperature., AMER INST PHYSICS, 英語

NONLINEAR PROPAGATION OF SOUND BEAM IN NONUNIFORM BUBBLY LIQUIDS
Tetsuya Kanagawa, Takeru Yano, Junya Kawahara, Kazumichi Kobayashi, Masao Watanabe, Shigeo Fujikawa, FLUID MEASUREMENTS AND INSTRUMENTATION CAVITATION AND MULTIPHASE FLOW ADVANCES IN FLUIDS ENGINEERING EDUCATION MICROFLUIDICS, VOL 2, 237, 241, 2012年, ［査読有り］
Nonlinear propagation of weakly diffracted sound beams in a weakly nonuniform bubbly liquid is analytically studied based on the method of multiple scales and scaling relations of some physical parameters. The system of basic equations consists of the conservation equations of mass and momentum for gas and liquid in a two-flui model, the Keller equation for bubble wall, the state equations for gas and liquid, and so on. The compressibility of liquid is taken into account and this leads to the wave attenuation due to bubble oscillations. It is assumed that the spatial distribution of the number density of bubbles in an initial state at rest is a slowly varying function of space coordinates and the amplitude of its variation is small compared with a mean number density. As a result, a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation with dispersion and nonuniform effects for a low frequency and long wavelength case and a nonlinear Schrodinger (NLS) equation with dissipation, diffraction, and nonuniform effects are derived from the basic equations., AMER SOC MECHANICAL ENGINEERS, 英語

ULTRASOUND BEAM RADIATED FROM CIRCULAR PISTON IN BUBBLY LIQUIDS: NONLINEAR ANALYSIS FOR ENVELOPE OF SHORT WAVES WITH DIFFRACTION EFFECT
Junya Kawahara, Tetsuya Kanagawa, Takeru Yano, Kazumichi Kobayashi, Masao Watanabe, Shigeo Fujikawa, FLUID MEASUREMENTS AND INSTRUMENTATION CAVITATION AND MULTIPHASE FLOW ADVANCES IN FLUIDS ENGINEERING EDUCATION MICROFLUIDICS, VOL 2, 251, 256, 2012年, ［査読有り］
A weakly diffracted ultrasound beam radiated from a circular piston placed in a bubbly liquid is formulated in terms of a wave equation based on scaling relations of physical parameters [1]: typical propagation speed, period, wavelength, and diameter of beam. We derive a nonlinear evolution equation for the modulation of quasi-monochromatic waves for the case of a short wavelength with a moderately high frequency from a set of basic equations for bubbly flows: conservation equations of mass and momentum for gas and liquid in a two-fluid model, Keller's equation for bubble wall motion, state equations for gas and liquid, and so on. The compressibility of liquid is taken into account, and thus the waves are attenuated due to bubble oscillations. The viscosity of gas, heat conduction in gas and liquid, and phase change across bubble wall are ignored. As a result, the nonlinear Schrodinger equation for the envelope of the beam with diffraction effect is derived from the basic equations. For plane waves the diffraction term does not appear, and hence our equation is reduced to the original nonlinear Schrodinger equation [1]., AMER SOC MECHANICAL ENGINEERS, 英語

J054032 気液界面で相変化をともなう共鳴音波に関する分子気体力学解析([J05403]マイクロ・ナノスケールの熱流体現象(3))
稲葉 匡司, 矢野 猛, 渡部 正夫, 小林 一道, 藤川 重雄, 年次大会 : Mechanical Engineering Congress, Japan, 2011, "J054032, 1"-"J054032-2", 2011年09月11日
The resonant gas oscillation excited in a one-dimensional space between an oscillating plate and a planer surface of a thin liquid layer on a quiescent rigid-wall is considered. Vapor flows with evaporation or condensation at the vapor-liquid interface are theoretically studied on the basis of a polyatomic version of Gaussian-BGK Boltzmann equation with a kinetic boundary condition including an evaporation coefficient., 一般社団法人日本機械学会, 日本語

J054031 音波共鳴法による水の蒸発係数測定([J05403]マイクロ・ナノスケールの熱流体現象(3))
中村 篤人, 矢野 猛, 小林 一道, 渡部 正夫, 藤川 重雄, 年次大会 : Mechanical Engineering Congress, Japan, 2011, "J054031, 1"-"J054031-4", 2011年09月11日
We propose a new method for measurement of the evaporation coefficient using sound resonance experiment based on a theory of molecular gas dynamics. The evaporation coefficient is one of the parameters contained in the kinetic boundary condition. The evaporation coefficient of water is determined from the pressure amplitude of resonant sound wave in a cylindrical space bounded by a sound source and a vapor-liquid interface. By comparing the pressure amplitude with a linear theory based on molecular gas dynamics, we prove that the evaporation coefficient of water is about 1.0 around 300K., 一般社団法人日本機械学会, 日本語

J054033 Enskog方程式を用いた高密度気体のCouette流れに関する数値計算([J05403]マイクロ・ナノスケールの熱流体現象(3))
小林 一道, 大橋 広太郎, 稲葉 匡司, 渡部 正夫, 藤川 重雄, 年次大会 : Mechanical Engineering Congress, Japan, 2011, "J054033, 1"-"J054033-5", 2011年09月11日
Numerical simulations for Couette flows in a dense gas are conducted based on the Enskog equation. In order to solve the Enskog equation, we use the particle scheme method, which is an extension of the well known DSMC method that is used to solve the Boltzmann equation. The results agree well with the solution of the Boltzmann equation, as the ratio of molecular diameter to the mean free path of the molecules, a/ A, becomes smaller. A thin layer is formed near a solid wall surface as the ratio al A becomes larger. We also find that the slip velocity on the solid surface depends on the ratio al A., 一般社団法人日本機械学会, 日本語

Application of multigrid ghost fluid method to the interaction of shock waves with bubbles in liquids
Kazumichi Kobayashi, Yoshinori Jinbo, Hiroyuki Takahira, Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, 77, 773, 20, 32, 2011年, ［査読有り］
A new numerical method based on the ghost fluid method was developed for compitssible two-phase flows
the idea of athptive mesh refinement with multigrid was implemented in the method. In the method, interpolation tecimiques between multiple grids near interfaces were also proposed. The present techniques are effective in diminishing the numerical instability caused by the discontinuity of physical variables across the interfaces. The bubble collapse induced by the interaction of an incident shock with a gas bubble in water was simulated with the present multigrid ghost fluid method. We have succeeded in capturing the fine interface and vortex structure during the collapsing and rebounding stage. The mass conservation is improved with the adaptive mesh refinement combined with the hybrid particle level set method. Also, the interaction of an incident shock wave with a gas bubble near a deformable boundary was simulated successfully with the method in which the motions of three phases, i.e., the gas inside the bubble, the ambient liquid, and the wall material, are taken into consideration. © 2011 The Japan Society of Mechanical Engineers., 日本語

403 ヒト爪郭部毛細血管・形状解析および赤血球・速度測定(バイオエンジニアリングI)
佐野 宏典, 矢口 久雄, 小林 一道, 渡部 正夫, 藤川 重雄, 北海道支部講演会講演概要集, 2010, 49, 83, 84, 2010年11月07日
一般社団法人日本機械学会, 日本語

303 マイクロ液滴噴霧洗浄技術開発のための高速ノズル流動解析(OS3. ナノ・マイクロ熱流動現象(1),オーガナイズドセッション講演)
高橋 広樹, 渡部 正夫, 小林 一道, 藤川 重雄, 計算力学講演会講演論文集, 2010, 23, 297, 298, 2010年09月23日
一般社団法人日本機械学会, 日本語

302 壁面に衝突する高速マイクロ液滴挙動に及ぼす液滴温度の効果(OS3. ナノ・マイクロ熱流動現象(1),オーガナイズドセッション講演)
ユ ヨンゼ, 渡部 正夫, 小林 一道, 藤川 重雄, 計算力学講演会講演論文集, 2010, 23, 295, 296, 2010年09月23日
一般社団法人日本機械学会, 日本語

1016 マルチグリッドGhost Fluid法を用いたゼラチン壁面近傍における気泡崩壊に関する数値解析(OS-5 可変形性境界を含む流れ(1))
神保 佳典, 周 正, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2010, 85, "10, 16", 2010年03月16日
一般社団法人日本機械学会, 日本語

1020 気液二相流中の圧力波の伝播に及ぼす気泡間相互作用の影響(OS-5 可変形性境界を含む流れ(2))
佐用 亮人, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2010, 85, "10, 26", 2010年03月16日
一般社団法人日本機械学会, 日本語

1023 気液二相ベンチュリ流れにおける気泡変形と液体ジェットの形成(OS-5 可変形性境界を含む流れ(3))
小林 一道, 梅山 和也, 西 亘, 野上 雅教, 高比良 裕之, 関西支部講演会講演論文集, 2010, 85, "10, 29", 2010年03月16日
一般社団法人日本機械学会, 日本語

S0507-2-3 縮小管内流れにおける気泡変形に関する実験的検討([S0507-2]気泡力学と界面現象(2))
西 亘, 野上 雅教, 小林 一道, 高比良 裕之, 年次大会講演論文集, 2010, 249, 250, 2010年
The bubble deformation in a gas-liquid contraction tube flow is observed with a high-speed camera to understand the mechanism of the bubble fission in the tube. It is shown that the surface instability occurs on the tip of a large bubble above the throat, which leads to the continuous detachment of small bubbles into the throat. Two kinds of liquid jets, ie, the forward jet and the counter jet, occur on the surface of small bubble in the throat. The result shows that the forward jet becomes faster as the bubble is pinched off more upstream. The forward jet can be caused by the pressure gradient behind the bubble. The result also shows that the counter jet occurs only when the L/R is small when L is the distance between the upstream and downstream bubbles and R is the bubble radius. The counter jet is caused by the deformation due to the bubble-bubble interaction., 一般社団法人日本機械学会, 日本語

S0507-2-1 直線状に配置された複数気泡と衝撃波との干渉に関する数値シミュレーション([S0507-2]気泡力学と界面現象(2))
森本 充洋, 神保 佳典, 小林 一道, 高比良 裕之, 年次大会講演論文集, 2010, 245, 246, 2010年
The present study is concerned with the interaction of an incident shock wave with in-line two bubbles by using the multi-grid ghost fluid method. The influence of the bubble-bubble distance on the formation of the liquid jets and the shock waves from the collapsing bubbles is investigated. It is shown that the collapse of the upstream bubble is decelerated by the rarefaction wave caused by the reflection of the incident shock wave at the surface of the downstream bubble. The shock waves generated by the collapse of the upstream bubble accelerate the collapse of the downstream bubble, which leads to the generation of higher internal gas pressure and faster liquid-jet velocity from the downstream bubble. It is also shown that there exists an initial bubble-bubble distance where the collapse of the downstream bubble is most accelerated., 一般社団法人日本機械学会, 日本語

マイクロ流体ネットワーク内における二相流に関する数値解析(マイクロ流体,一般講演)
二木 和宏, 小林 一道, 日本流体力学会年会講演論文集, 2010, 97, 97, 2010年
In the present study, numerical simulations are conducted for the gas-liquid two-phase flow in a microfluidic network using a compact model proposed by F. Jousse et al. The aim of the present study is to examine the influence of bubble behavior (dispersed phase) on the flow rates in a microfluidic network. The result shows that the flow rates in the microfluidic network can be controled by changing the void fraction of dispersed phase at the inlet. Also the compact model is capable of explaining the experimental results of Microfluidic bubble logic shown by M. Prakash et al. qualitatively., 日本流体力学会, 日本語

蒸発・凝縮をともなう共鳴音波に関する弱非線形解析(分子スケール(1),一般講演)
稲葉 匡司, 矢野 猛, 渡部 正夫, 小林 一道, 藤川 重雄, 日本流体力学会年会講演論文集, 2010, 102, 102, 2010年
The behavior of resonant sound waves in a finite one-dimensional space between an oscillating plate (sound source) and a vapor-liquid interface is analyzed by applying the asymptotic theory for Kn<

非線形共鳴音波を用いた蒸発係数測定法(相変化,一般講演)
中村 篤人, 矢野 猛, 小林 一道, 渡部 正夫, 藤川 重雄, 日本流体力学会年会講演論文集, 2010, 283, 283, 2010年
We propose a new method for measurement of the evaporation coefficient using nonlinear sound resonance experiment based on a theory of molecular gas dynamics. The evaporation coefficient is determined from the pressure amplitude of second harmonics generated by the nonlinear effect of resonant sound wave in a cylindrical space bounded by a sound source and a gas-liquid interface. To demonstrate the applicability of this method, we conduct a test experiment. As a result, we confirm the increase of second harmonics amplitude caused by the sound resonance., 日本流体力学会, 日本語

2006 生体組織近傍での複数気泡の崩壊 : 生体組織に及ぼす気泡間相互作用の効果(OS20.細胞・生体分子の計算バイオメカニクス(2),オーガナイズドセッション)
神保 佳典, 周 正, 小林 一道, 高比良 裕之, 計算力学講演会講演論文集, 2009, 22, 554, 555, 2009年10月10日
一般社団法人日本機械学会, 日本語

2005 マルチグリッドGhost Fluid法による生体組織近傍の気泡崩壊現象に関する数値計算 : 2つのLevel Set関数による界面捕獲法の適用(OS20.細胞・生体分子の計算バイオメカニクス(2),オーガナイズドセッション)
小林 一道, 高比良 裕之, 計算力学講演会講演論文集, 2009, 22, 552, 553, 2009年10月10日
一般社団法人日本機械学会, 日本語

1004 ベンチュリ管内の気液二相流における気泡崩壊と圧力波の伝播に関する実験(OS-5 界面が関わる複雑熱流体現象(1))
野上 雅教, 梅山 和也, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2009, 84, "10, 4", 2009年03月16日
一般社団法人日本機械学会, 日本語

1003 Ghost Fluid法を用いた縮小管内の気泡の変形挙動に関する数値計算(OS-5 界面が関わる複雑熱流体現象(1))
柴原 大吉, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2009, 84, "10, 3", 2009年03月16日
一般社団法人日本機械学会, 日本語

1012 固体壁上における薄い液膜の蒸発・凝縮に関する分子動力学的研究(OS-5 界面が関わる複雑熱流体現象(3))
山口 佳昭, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2009, 84, "10, 12", 2009年03月16日
一般社団法人日本機械学会, 日本語

1006 界面活性剤に覆われたマイクロバブルの成長過程に関する検討(OS-5 界面が関わる複雑熱流体現象(2))
入江 茉耶, 佐用 亮人, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2009, 84, "10, 6", 2009年03月16日
一般社団法人日本機械学会, 日本語

28aTK-11 固体壁面上における薄い液膜からの蒸発・凝縮現象に関する分子動力学シミュレーション(28aTK 波動,輸送・拡散,領域11(統計力学,物性基礎論,応用数学,力学,流体物理))
小林 一道, 山口 佳昭, 高比良 裕之, 日本物理学会講演概要集, 64, 1, 289, 289, 2009年03月03日
一般社団法人日本物理学会, 日本語

分子動力学法による薄い液膜の気液界面における気体論境界条件の検証(反応・多相系 相変化,一般講演)
小林 一道, 山口 佳昭, 高比良 裕之, 日本流体力学会年会講演論文集, 2009, 218, 218, 2009年
In the present study, the kinetic boundary condition for the Boltzmann equation at a vapor-liquid interface of thin liquid layer on a solid wall is investigated using molecular dynamics simulations. The vapor and liquid are composed of argon molecules and the solid wall is composed of platinum molecules. Two kinds of energy parameter of L-J potential between argon and platinum are chosen for the simulations with different wetability. The results show that the kinetic boundary condition for the vapor-liquid system is applicable to the vapor-liquid-solid system as long as the liquid layer is about 6 times larger than the molecular diameter because the velocity components in every direction obey the Maxwellian and the evaporation coefficient for the vapor-liquid-solid system coincides with that for the vapor-liquid system., 日本流体力学会, 日本語

J0201-1-4 界面活性剤で覆われたマイクロバブルの成長・収縮に及ぼす気体拡散の影響(ドラッグデリバリーシステムとその周辺技術の基礎と展開(1))
佐用 亮人, 入江 茉耶, 小林 一道, 高比良 裕之, 年次大会講演論文集, 2009, 103, 104, 2009年
The growth and shrinkage of surfactant-coated microbubbles are observed with a high-speed video camera. The observed bubble motion is compared with the simulation in which the dynamic surface tension and the variation of gas permeation resistance of surfactant layers are considered. The simulation is in good agreement with the experiment. It is shown that when the microbubble grows under pressure reduction, the gas diffusion from the surrounding liquid to bubble inside is suppressed by the increase of the surface tension, while it is promoted by the decrease of the gas permeation resistance. On the other hand, the bubble shrinkage due to gas diffusion after pressure increase is strongly affected by the increase of the gas permeation resistance. The variations of both the surface tension and the gas permeation resistance determine the diffusion process of microbubbles., 一般社団法人日本機械学会, 日本語

754 生体壁近傍での気泡の崩壊 : Ghost Fluid法を用いた数値シミュレーション(OS21.細胞・生体分子の計算バイオメカニクス(4),オーガナイズドセッション)
周 正, 松野 孝浩, 小林 一道, 高比良 裕之, 計算力学講演会講演論文集, 2008, 21, 871, 872, 2008年11月01日
一般社団法人日本機械学会, 日本語

(8)衝撃波管管端でのメタノール蒸気の凝縮過程に関する分子気体力学解析(論文,日本機械学会賞〔2007年度(平成19年度)審査経過報告〕)
矢野 猛, 小林 一道, 藤川 重雄, 日本機械学會誌, 111, 1074, 375, 375, 2008年05月05日
一般社団法人日本機械学会, 日本語

509 Ghost Fluid法を用いたゼラチン壁近傍での気泡崩壊に関する数値計算(OS-7 熱流体の非線形力学とその数値シミュレーション(1))
周 正, 松野 孝浩, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2008, 83, "5, 11", 2008年03月14日
一般社団法人日本機械学会, 日本語

508 ガラス壁近傍における水銀中での衝撃波と気泡との干渉に関する軸対称数値計算(OS-7 熱流体の非線形力学とその数値シミュレーション(1))
松野 孝浩, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2008, 83, "5, 10", 2008年03月14日
一般社団法人日本機械学会, 日本語

403 ベンチュリー管を用いた気液二相流における気泡微細化の機構に関する実験的検討(OS-3 複雑流体現象(1))
梅山 和也, 池間 賢吾, 小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2008, 83, "4, 3", 2008年03月14日
一般社団法人日本機械学会, 日本語

518 気液界面での相変化を伴う気泡の崩壊現象に関する分子気体力学に基づく数値シミュレーション(OS-7 熱流体の非線形力学とその数値シミュレーション(3))
小林 一道, 高比良 裕之, 関西支部講演会講演論文集, 2008, 83, "5, 25", 2008年03月14日
一般社団法人日本機械学会, 日本語

1616 Ghost Fluid法による気泡崩壊の生体組織への影響に関する数値計算(S22 ドラッグデリバリーシステムと流体力学,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)
周 正, 松野 孝浩, 小林 一道, 高比良 裕之, 年次大会講演論文集, 2008, 29, 30, 2008年
In the present study, numerical simulations are conducted for the collapse of an air bubble near a tissue surface by using an improved ghost fluid method. A tissue is modeled with a gelatin that was used in the experiment by Kodama and Takayama. The bubble collapse is induced by the interaction between a bubble and an incident shock wave. A flat shock wave profile and an exponential one based on the experimemt by Kodama and Takayama are utilized, and the influence of the shock wave profile on the dynamical motion of the bubble and gelatin is investigated. It is shown that the gelatin surface is depressed by the shock waves generated from the bubble. The penetration of the bubble into the depression of the gelatin, which was demonstrated in the experiment by Kodama and Takayama, is simulated successfully. The results also show that the collapse time of a bubble is longer and the width of the depression is thinner when the shcok wave with the exponential profile interacts with the bubble., 一般社団法人日本機械学会, 日本語

1115 分子気体力学に基づく相変化を伴う単一気泡運動の数値シミュレーション(2)(OS11-3 ナノ・マイクロフルイディクス(マイクロ混相流),OS11 ナノ・マイクロフルイディクス,オーガナイズドセッション)
小林 一道, 高比良 裕之, 流体工学部門講演会講演論文集, 2007, "1115, 1"-"1115-4", 2007年11月17日
The collapse and rebound of a spherical bubble filled with a noncondensable gas or condensable gas (vapor) were investigated by combining bubble dynamics and molecular gas dynamics. The polyatomic version of Gaussian-BGK Boltzmann equation was utilized for a gases vapor inside the bubble, while Fujikawa & Akamatsu's equation was utilized for the motion of the bubble. These equations were solved numerically with the kinetic boundary condition including a condensation coefficient that is an important parameter for phase change processes. The result shows that the condensation at a vapor-liquid interface of a vapor bubble is essential for the mechanism of collapse and rebound of the bubble., 一般社団法人日本機械学会, 日本語

206 弱い音波を用いた液体の蒸発係数測定法の開発(OS-2 マイクロ・ナノ流体工学(2))
中村 篤人, 小林 一道, 稲葉 匡司, 矢野 猛, 藤川 重雄, 関西支部講演会講演論文集, 2007, 82, "2, 6", 2007年03月16日
一般社団法人日本機械学会, 日本語

ベストプレゼンテーション賞を受賞して
小林 一道, 熱物性 : Japan journal of thermophysical properties, 21, 1, 55, 55, 2007年02月28日
日本語

303 分子気体力学解析と衝撃波管実験によるメタノールと水の気体論境界条件の確立(2)(OS3-1 マイクロ・ナノフルイズ,OS3 マイクロ・ナノフルイズ,オーガナイズドセッション)
小林 一道, 渡邉 俊介, 稲葉 匡司, 矢野 猛, 藤川 重雄, 一條 真古人, 流体工学部門講演会講演論文集, 2006, "303, 1"-"303-4", 2006年10月28日
The present paper aims at establishing kinetic boundary conditions of methanol and water through the determination of condensation coefficients based on molecular gas dynamics analysis and shock tube experiment in weak vapor-liquid nonequilibrium states. The results show that, when the ratio of vapor pressure to saturated vapor pressure at the interface is close to unity, values of condensation coefficients of methanol and water equal to evaporation coefficient estimated by the resent molecular dynamics analysis. As the ratio becomes large, the condensation coefficients decrease. The pressure ratio dependency of a condensation coefficient is explained by the molecular gas dynamics analysis., 一般社団法人日本機械学会, 日本語

303 分子気体力学解析と衝撃波管実験によるメタノールと水の気体論境界条件の確立(1)(OS3-1 マイクロ・ナノフルイズ,OS3 マイクロ・ナノフルイズ,オーガナイズドセッション)
小林 一道, 渡邉 俊介, 稲葉 匡司, 矢野 猛, 藤川 重雄, 一條 真古人, 流体工学部門講演会講演論文集, 2006, "303, a", 2006年10月28日
一般社団法人日本機械学会, 日本語

Preliminary experience with minimally invasive video-assisted surgery for thymic diseases, including myasthenia gravis, through a horizontal ministernotomy
M Watanabe, R Yozu, K Kobayashi, JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY, 130, 3, 912, +, 2005年09月
MOSBY-ELSEVIER, 英語, その他

925 メタノールの凝縮係数の決定 : 衝撃波管の実験に対する分子気体力学解析(J14-3 量子・分子熱流体工学(3),J14 量子・分子熱流体工学,2005年度年次大会)
小林 一道, 三上 悟, 太田 樹, 矢野 猛, 藤川 重雄, 一條 眞古人, 年次大会講演論文集, 2005, 87, 88, 2005年
We perform the determination of the condensation coefficient for methanol by combining a numerical analysis based on the molecular gas dynamics and shock tube experiment. In the numerical analysis, the boundary condition for the Boltzmann equation at the vapor liquid interface is rewritten using the net mass flux obtained from the shock tube experiment. Thereby, the condensation coefficient is determined by the vapor-liquid system. The result shows that the value of the condensation coefficient for methanol ranges from 0.7 to 0.9, and it is close to that of the evaporation coefficient evaluated by the recent molecular dynamics simulation., 一般社団法人日本機械学会, 日本語

924 メタノール蒸気の凝縮係数の決定 : 衝撃波管管端における液膜成長の光干渉計による測定(J14-3 量子・分子熱流体工学(3),J14 量子・分子熱流体工学,2005年度年次大会)
三上 悟, 大田 樹, 小林 一道, 藤川 重雄, 矢野 猛, 一條 眞古人, 年次大会講演論文集, 2005, 85, 86, 2005年
The condensation coefficient is obtained by combining a shock tube experiment and the corresponding numerical analysis based on the Gaussian-BGK Boltzmann equation. In the experiment, the liquid film growth on the shock tube endwall behind the reflected shock wave is measured with a high accuracy by an optical interferometer. The interferometer system is improved, which enables us to combine the experiment and numerical analysis more closely. The results show that the condensation coefficient of methanol takes values from 0.7 to 0.9 in nonequilibrium states, and the values are close to that of evaporation coefficient evaluated by molecular dynamics simulations., 一般社団法人日本機械学会, 日本語

Condensation of methanol vapor onto its liquid film on a solid wall behind a reflected shock wave
T Yano, K Kobayashi, S Fujikawa, Rarefied Gas Dynamics, 762, 208, 213, 2005年, ［査読有り］
On the basis of the polyatomic gas version of the Gaussian-BGK model of the Boltzmann equation, we shall numerically analyze the condensation of methanol vapor onto its liquid film on an endwall of the shock tube induced by the pressure elevation due to a reflected shock wave. By comparing the numerical results with experimental ones, we can determine the value of condensation coefficient in various nonequilibrium conditions. It is shown that at around room temperature, the condensation coefficient of methanol vapor is almost unity when the condensation is sufficiently weak. In this case, the asymptotic analysis for the steady problem gives an appropriate estimation for the rate of the growth of the liquid film thickness., AMER INST PHYSICS, 英語

28pWD-12 液膜で反射した衝撃波に誘起される多原子分子蒸気の凝縮過程の気体論方程式に基づく数値解析(乱流と輸送(乱流・輸送現象))(領域11)
小林 一道, 矢野 猛, 藤川 重雄, 日本物理学会講演概要集, 59, 1, 299, 299, 2004年03月03日
一般社団法人日本物理学会, 日本語

分子気体力学に基づく多原子分子気体を伝播する平面衝撃波の数値解析(S27-2 熱流体現象に対する分子気体力学および分子動力学法の応用(2),S27 熱流体現象に対する分子気体力学および分子動力学法の応用)
小林 一道, 矢野 猛, 藤川 重雄, 年次大会講演論文集, 2004, 373, 374, 2004年
Numerical analysis is performed for a normal shock wave in a polyatomic molecule gas based on molecular gas dynamics, where the polyatomic gas is taken to be nitrogen. We adopt the polyatomic version of Gaussian-BGK Boltzmann equation for nitrogen gas and it is solved numerically with a finite difference method. The results agree well with the experimental results by Robben and Talbot (1966) at the shock Mach number 1.71. Furthermore, we examine the transition of rotational energy in the shock wave in terms of velocity distribution functions., 一般社団法人日本機械学会, 日本語

517 反射衝撃波背後で起こる多原子分子蒸気の凝縮現象の数値シミュレーション
小林 一道, 矢野 猛, 藤川 重雄, 北海道支部講演会講演概要集, 2003, 43, 196, 197, 2003年09月28日
一般社団法人日本機械学会, 日本語

702 衝撃波管内部のメタノール蒸気の凝縮現象の数値解析
小林 一道, 矢野 猛, 藤川 重雄, 流体工学部門講演会講演論文集, 2003, 94, 94, 2003年09月18日
一般社団法人日本機械学会, 日本語

406 気液非平衡状態における多原子分子蒸気の相変化の分子気体力学シミュレーション
小林 一道, 矢野 猛, 藤川 重雄, 北海道支部講演会講演概要集, 2002, 42, 114, 115, 2002年10月05日
一般社団法人日本機械学会, 日本語

蒸発・凝縮を伴う球形気泡の崩壊現象における凝縮係数の影響　　　　　　　　　　　　　　　
S. Morikawa, Y. Tatekura, K. Kobayashi, H. Fujii, M. Watanabe, K. Sasaki
日本流体力学会 「ながれ」, 2017年05月, 105-108, 日本語, 学術書, ながれ NAGARE 36, ［共著］

Liquid temperature dependence of kinetic boundary condition at vapor–liquid interface　　　　　　　　　　　　　　　
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
Advanced in Engineering, 2017年03月, 英語, 調査報告書, https://advanceseng.com/mechanical-engineering/liquid-temperature-dependence-kinetic-boundary-condition-vapor-liquid-interface/, ［共著］

北海道大学大学院工業研究院 機械宇宙工学部門 流体力学研究室　　　　　　　　　　　　　　　
渡部正夫, 小林一道, 藤井宏之
混相流 Vol.30 No.4 日本混相流学会, 2016年12月, ［共著］

気液界面での質量・運動量・エネルギーの輸送 ―分子動力学，分子気体力学，実験の融合― 第5章 蒸発・凝縮の衝撃波管による実験　　　　　　　　　　　　　　　
小林一道, 藤川重雄
日本流体力学会，ながれ, 2014年12月, 543-548, 日本語, 学術書, ながれ Nagare 33, ［共著］

日本混相流学会 混相流シンポジウム２０１４ 報告　　　　　　　　　　　　　　　
村井祐一, 小林一道
混相流 Vol.28 No.4 日本混相流学会, 2014年12月, 4, 日本語

気液界面での質量・運動量・エネルギーの輸送 ―分子動力学，分子気体力学，実験の融合― 第4章 蒸発・凝縮への分子気体力学の適用　　　　　　　　　　　　　　　
小林一道, 藤川重雄
日本流体力学会，ながれ, 2014年10月, 453-459, ながれ NAGARE 33, ［共著］

気液界面ダイナミクスのマルチスケール解析　　　　　　　　　　　　　　　
小林一道
えんじにあRing 北海道大学工学研究院・工学院 広報誌, 2013年10月, 1, https://www.eng.hokudai.ac.jp/engineering/2013-10/index.html

相互作用を考慮した球形気泡離散モデルの解析（気泡流の音響特性）　　　　　　　　　　　　　　　
川原潤也, 小林一道, 渡部正夫
京都大学数理解析研究所講究録, 2013年

蒸発・凝縮をともなう非線形共鳴音波　　　　　　　　　　　　　　　
稲葉匡司, 矢野猛, 小林一道, 渡部正夫
日本流体力学会，ながれ, 2012年12月, 487-490, 日本語, 学術書, ながれ NAGARE 31, ［共著］

流体物理洗浄の概要と水蒸気二流体ジェットでの適用例　　　　　　　　　　　　　　　
真田俊之, 小林一道, 林田充司
産業洗浄, 2012年, 14-19, ［共著］

気泡力学へのGhost Fluid法の適用　　　　　　　　　　　　　　　
高比良裕之, 小林一道
日本機械学会 流体工学部門 ニューズレター「流れ」9月号, 2009年, 日本語, http://www.jsme-fed.org/newsletters/2009_9/no5.html#ctop

Handbook of Interferometers: Research, Technology and Application　　　　　　　　　　　　　　　
Nova Science Publishers, 2009年, 9781607410508

Mean-field kinetic theory analysis of vapor condensation induced by fast-moving liquid film
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
AJK-FED 2023, 2023年07月11日, 英語, 口頭発表（一般）
2023年07月09日 - 2023年07月13日, 33844587

Condensation Induced by Rapidly Moving Liquid Film Surrounded by Vapor and Non-condensable Gas
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
32nd International Symposium on Rarefied Gas Dynamics, 2022年07月05日, 英語, 口頭発表（一般）
2022年07月04日 - 2022年07月08日, 33844587

Mean-Field Kinetic Theory Analysis of Evaporation Coefficient and Condensation Coefficient of Vapor Molecules in the Presence of NonCondensable Gas under Non-Equilibrium Conditions
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
Pre-RGD32 Online Workshop on Recent Hot Topics in Rarefied Gas Dynamics, 2021年07月07日, 英語, 口頭発表（一般）
2021年07月07日 - 2021年07月09日, 33844587

Numerical simulation of vapor bubble collapse with a small amount of non-condensable gas based on molecular gas dynamics　　　　　　　　　　　　　　　
Kazumichi Kobayashi
Japan-Korea CFD Workshop, 2019年11月27日, 英語, 口頭発表（招待・特別）
［招待講演］, ［国際会議］

Surrounding gas-independent splash at high-velocity drop impact with a projected smooth solid surface　　　　　　　　　　　　　　　
M. Watanabe, T. Ashida, K. Kobayashi, H. Fujii, T. Sanada
The 72nd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics, 2019年11月23日, 英語, 口頭発表（一般）
［国際会議］

Molecular Dynamics Study on Influence of Liquid-solid Intermolecular Force on Levitating Mechanism of Impacting Nanodroplet on Heated Wall　　　　　　　　　　　　　　　
H. Tabe, K. Kobayashi, H. Yaguchi, H. Fujii, M. Watanabe
Surface Wettability Effects on Phase Change Phenomena(SWEP), 2019年06月06日, 英語, ポスター発表
［国際会議］

Molecular Gas Dynamics Analysis of Vapor-Gas Flow inside Collapsing Bubble　　　　　　　　　　　　　　　
K. Yamamot, K. Kobayashi, H. Fujii, M. Watanabe, M. Kon, H. Takahira
31th International Symposium on Rarefied Gas Dynamics (RGD31), 2018年07月, 英語, 口頭発表（一般）
［国際会議］

Influence of Surface Roughness of High Temperature Wall on Levitation of Impacting Droplet Based on Molecular Dynamics Simulation　　　　　　　　　　　　　　　
H. Tabe, K. Kobayashi, H. Yaguchi, H. Fujii, M. Watanabe
Surface Wettability Effects on Phase Change Phenomena(SWEP), 2018年05月, 英語, ポスター発表
SWEP BOOK of Abstract, p. 27, ［国際会議］

Molecular Dynamics Study of Droplet Impact on High-Temperature Wall　　　　　　　　　　　　　　　
H. Tabe, K. Kobayashi, H. Yaguchi, H. Fujii, M. Watanabe
The 7th East Asia Mechanical and Aerospace Engineering Workshop, 2017年11月, 英語, 口頭発表（一般）
1 page, ［国際会議］

Numerical Investigation of Light and Pressure Propagation in Biological Tissue for Model-Based Photoacoustic Tomography　　　　　　　　　　　　　　　
K. Tabayashi, H. Fujii, K. Kobayashi, M. Watanabe
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-1526, 4 pages, ［国際会議］

Numerical and Experimental Analysis of Droplet Impact in Vapor Environment　　　　　　　　　　　　　　　
S. Sawai, T. Isono, H. Fujii, K. Kobayashi, M. Watanabe, T. Sanada
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-1491, 5 pages, ［国際会議］

Does Chemical Properties of Solid Surface Cause Liquid Film Flow Instability at Droplet Impact?　　　　　　　　　　　　　　　
S. Tanimoto, M. Watanabe, K. Kobayashi, H. Fujii, T. Sanada
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-­1334, 4 pages, ［国際会議］

Observation of Splash Generated Immediately After the Impact of a High-Speed Droplet in Reduced-Pressure　　　　　　　　　　　　　　　
T. Ashida, M. Watanabe, K. Kobayashi, H. Fujii, T. Sanada
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-­1485, 4 pages, ［国際会議］

Micro-Droplets Generation Induced by Interactions Between Focused Ultrasound and a Liquid Surface　　　　　　　　　　　　　　　
K. Seko, K. Kobayashi, H. Fujii, M. Watanabe
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-1173, 3 pages, ［国際会議］

Molecular Dynamics Simulation of the Role of the Wettability in the Droplet Impact on a High-Temperature Wall　　　　　　　　　　　　　　　
H. Tabe, K. Kobayashi, H. Yaguchi, H. Fujii, M. Watanabe
The Ninth JSME-KSME Thermal and Fluids Engineering Conference, 2017年10月, 英語, 口頭発表（一般）
TFEC9-1492, 4 pages, ［国際会議］

気液界面での熱･物質輸送を考慮したマイクロバ ブル崩壊現象の分子流体力学解析　　　　　　　　　　　　　　　
小林 一道
日本機械学会年次大会2017, 2017年09月04日, 日本語, 口頭発表（招待・特別）
【招待講演】, ［招待講演］, ［国内会議］

蒸気雰囲気中の液滴衝突に関する実験・分子流体力学解析　　　　　　　　　　　　　　　
小林 一道
若手研究者夏季セミナー（混相流シンポジウム2017）, 2017年08月21日, 日本語, 口頭発表（招待・特別）
【招待講演】, ［招待講演］, ［国内会議］

Numerical simulation of spherical vapor-gas bubble collapse　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Misaki Kon, Takahiro Nagayama, Hiroyuki Fujii, Masao Watanabe, Hiroyuki Takahirav
Japan-U.S. Seminar on Two-Phase Flow Dynamics, 2017年06月22日, 英語, 口頭発表（招待・特別）
【招待講演】, ［招待講演］, ［国際会議］

Numerical simulation of pressure generated at the liquid droplet impact on a solid surface　　　　　　　　　　　　　　　
Y. Tatekura, M. Watanabe, K. Kobayashi, T. Sanada
The 3rd International Conference on Numerical Methods in Multiphase Flows, 2017年06月, 英語, 口頭発表（一般）
B62, 2 pages, ［国際会議］

Quantitative Method to Determine the Optical Properties of Melons by the Photon Diffusion Equation　　　　　　　　　　　　　　　
K. Hattori, H. Fujii, G. Nishimura, K. Kobayashi, M. Watanabe
The 5th Asian NIR Symposium, 2016年11月, 英語, 口頭発表（一般）
［国際会議］

Optical properties of melons determined by an analysis based on the photon diffusion equation　　　　　　　　　　　　　　　
K. Hattori, H. Fujii, G. Nishimura, K. Kobayashi, M. Watanabe
1st Food Chemistry Conference, 2016年10月, 英語, 口頭発表（一般）
［国際会議］

気液界面のナノスケール熱流体力学　　　　　　　　　　　　　　　
小林 一道
日本機械学会2016年度年次大会 流体工学部門企画 複雑流動現象の解析技術と学理構築 （Ⅰ マイクロ流れ，分子流，機能性流体）, 2016年09月12日, 日本機械学会, 日本語, 口頭発表（招待・特別）
九州大学伊都キャンパス, 【招待講演】, ［招待講演］, ［国内会議］

Molecular simulation of evaporation mass flux during net evaporation/condensation
Misaki Kon, Kobayashi Kobayashi, Masao Watanabe
The 30th International Symposium on Rarefied Gas Dynamics, 2016年07月10日, 英語, 口頭発表（一般）
University of Victoria Victoria BC Canada, AIP Conf. Proc., Vol. 1786, 110001 (2016), ［国際会議］

Molecular dynamics simulation on kinetic boundary conditions of gas-vapor binary mixture
Kazumichi Kobayashi, Kiyofumi Sasaki, Misaki Kon, Hiroyuki Fujii, Masao Watanabe
The 30th International Symposium on Rarefied Gas Dynamics, 2016年07月10日, 英語, 口頭発表（一般）
University of Victoria Victoria BC Canada, AIP Conf. Proc., 1786, 110002, (2016), ［国際会議］

Effects of surrounding gas temerature on ethanol droplet impact on solid surface　　　　　　　　　　　　　　　
T. Isono, M. Watanabe, K. Kobayashi, H. Fujii, T. Sanada
9th International conference on multiphase flow (ICMF2016), 2016年05月, 英語, 口頭発表（一般）
［国際会議］

Observation of non-sperical droplet imacts with velocities of O(10 m/s)　　　　　　　　　　　　　　　
Y. Kataoka, Y. Hori, M. Watanabe, K. Kobayashi, H. Fujii, T. Sanada
9th International conference on multiphase flow (ICMF2016), 2016年05月, 英語, 口頭発表（一般）
［国際会議］

Numerical analysis of bubble dynamics with vapor-liquid boundary conditions derived from molecular gas dynamics　　　　　　　　　　　　　　　
S. Morikawa, J. Jinbo, Y. Tatekura, K. Kobayashi, M. Watanabe, H. Fujii, K. Sasaki
9th International conference on multiphase flow (ICMF2016), 2016年05月, 英語, 口頭発表（一般）
［国際会議］

Numerical simulation of vapor-gas bubble dynamics based on molecular gas dynamics　　　　　　　　　　　　　　　
T. Nagayama, M. Kon, K. Kobayashi, M. Watanabe, H. Fujii, H. Takahira
9th International conference on multiphase flow (ICMF2016), 2016年05月, 英語, 口頭発表（一般）
［国際会議］

Molecular Dynamics Simulation on Kinetic Boundary Conditions of Gas-Vapor Binary Mixture
Kazumichi Kobayashi, Kiyofumi Sasaki, Misaki Kon, Hiroyuki Fujii, Masao Watanabe
30TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS (RGD 30), 2016年, AMER INST PHYSICS, 英語
2016年 - 2016年, The aim of this study is to construct the kinetic boundary condition for Ar-Ne binary mixture in equilibrium using molecular dynamics (MD) simulations. The temperature of the MD simulation system is 85 K; Ar molecules behave as condensable gas (vapor), and Ne molecules behave as non-condensable gas (gas). In this simulation, we utilize the two-boundary method improved by our previous study to investigate behaviors of Ar and Ne molecules at the interface. From the results, we can obtain the molecular mass fluxes at the interface, and evaluate the values of evaporation and condensation coefficients of Ar (vapor) and Ne (gas) molecules.

Microscopic Investigation of Boundary Condition at Vapor-liquid Interface during Unsteady Evaporation and Condensation
Misaki Kon, Kobayashi Kobayashi, Masao Watanabe
2nd European conference on non-equilibrium gas flow, 2015年12月08日, 英語, 口頭発表（一般）
Eindhoven, the Netherlands, Proceedings of 2nd European conference on non-equilibrium gas flow, No. 50, 1 page., ［国際会議］

Numerical simulation of bubble collapse and the transfer of vapor and noncondensable gas through the bubble interface using the ghost fluid method
Y Jinbo, K Kobayashi, M Watanabe, H Takahira
Journal of Physics: Conference Series, 2015年12月03日, IOP Publishing, 英語
2015年12月03日 - 2015年12月03日, The ghost fluid method is improved to include heat and mass transfer across the gas-liquid interface during the bubble collapse in a compressible liquid. This transfer is due to both nonequilibrium phase transition at the interface and diffusion of the noncondensable gas across the interface. In the present method, the ghost fluids are defined with the intention of conserving the total mass, momentum, and energy, as well as the mass of each component while considering the heat and mass fluxes across the interface. The gas phase inside the bubble is a mixture of vapor and noncondensable gas, where binary diffusion between the mixture components is taken into account. The gas diffusion in the surrounding liquid is also considered. This method is applied to a simulation of a single spherical bubble collapse with heat and mass transfer across the interface in a compressible liquid. When noncondensable gas is present, it accumulates near the interface due to vapor condensation, thereby preventing further condensation. This results in a weaker bubble collapse than the case without noncondensable gas.

Numerical simulation of bubble collapse and tranfer of vapor and noncondensable gas through the bubble interface using the ghost fluid method　　　　　　　　　　　　　　　
Y. Jinbo, K. Kobayashi, M. Watanabe, H. Takahira
9th International symposium on cavitation (CAV2015), 2015年12月, 英語, 口頭発表（一般）
［国際会議］

Study on Pressure Wave Propagation in a Liquid Containing Spherical Bubbles in a Rectangular Duct　　　　　　　　　　　　　　　
J. Kawahara, M. Watanabe, K. Kobayashi
9th International symposium on cavitation (CAV2015), 2015年12月, 英語, 口頭発表（一般）
［国際会議］

Numerical study of Light Propagation in Agricultural Products for Non-destructive Assessment of Food Quality　　　　　　　　　　　　　　　
K. Hattori, H. Fujii, Y. Tatekura, K. Kobayashi, M. Watanabe
Biophotonics Japan, 2015年10月, 英語, 口頭発表（一般）
［国際会議］

Numerical simulation of compressible two-phase flows in high-speed impingement of a hollow droplet on a solid wall　　　　　　　　　　　　　　　
Y. Jinbo, K. Kobayashi, M. Watanabe, T. Sanada
EMN Meeting on Droplets, 2015年05月, 英語
【Invited】Total 1 page, ［招待講演］, ［国際会議］

Numerical study of light propagation in agricultural products for non-destructive assessment of food quality
Kiyohito Hattori, Hiroyuki Fujii, Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe
BIOPHOTONICS JAPAN 2015, 2015年, SPIE-INT SOC OPTICAL ENGINEERING, 英語
2015年 - 2015年, An accurate determination of optical properties of agricultural products is crucial for non-destructive assessment of food quality. For the determination, light intensity is measured at the surface of the product; then, inverse analysis is employed based on a light propagation model such as the radiative transfer equation (RTE). The inverse analysis requires high computational loads because the light intensity is numerically calculated using the model every time the optical properties are changed. For the calculation, we propose an efficient technique by combining a numerical solution with an analytical solution of the RTE, and investigate the validity of the technique in a two-dimensional homogeneous circular medium which is regarded as a light propagation model with optical properties of kiwifruit. The proposed technique can provide accurate results of the light intensity in change of the optical properties, and the accuracy is less dependent on the boundary conditions and source-detector angles. In addition, the technique can reduce computation time compared with that for numerical calculation of the RTE. These results indicate usefulness of the proposed technique for the inverse analysis.

Molecular dynamics simulation on evaporation molecules in a vapor-liquid equilibrium state　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Kazumasa Hori, Hisao Yaguchi, Masao Watanabe
THE 29TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 2014年07月13日, 英語, 口頭発表（一般）
Xi'an, China, AIP Conf. Proc. 1628, 404 (2014); http://dx.doi.org/10.1063/1.4902621, ［国際会議］

Numerical analysis of kinetic boundary conditions at net evaporation/condensation interfaces in various liquid temperatures based on mean-field kinetic theory　　　　　　　　　　　　　　　
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
THE 29TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 2014年07月13日, 英語, 口頭発表（一般）
Xi'an, China, AIP Conf. Proc. 1628, 398 (2014); http://dx.doi.org/10.1063/1.4902620, ［国際会議］

Acoustic Characteristics of Compressible Bubbly Liquids: Study Based on Equation of Motion of Spherical Bubbles　　　　　　　　　　　　　　　
Junya KAWAHARA, Kazumichi KOBAYASHI, Masao WATANABE
8th International Conference on Multiphase Flow, 2013年05月23日, 英語
No. 260, Total 5 pages, ［国際会議］

Numerical simulations of impact pressure generated by single-droplet impact　　　　　　　　　　　　　　　
Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe
8th International Conference on Multiphase Flow, 2013年05月23日, 英語, 口頭発表（一般）
No. 521, Total 5 pages, ［国際会議］

Numerical analysis of nonequilibrium phase change phenomena between two liquid slabs with different temperature　　　　　　　　　　　　　　　
Kon M, Kobayashi K, Watanabe M
13th UK Heat Transfer conference, 2013年, 英語
No. 41, Total 6 pages, 2013, ［国際会議］

Numerical analysis of vapor-liquid two-phase system based on the Enskog-Vlasov equation　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Kotaro Ohashi, Masao Watanabe
THE 28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 2012年07月, 英語, 口頭発表（一般）
AIP Conf. Proc., ［国際会議］

Nonlinear Resonant Gas Oscillation Accompanied with Evaporation and Condensation　　　　　　　　　　　　　　　
Masashi Inaba, Takeru Yano, Kazumichi Kobayashi, Masao Watanabe
THE 28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS, 2012年07月, 英語, 口頭発表（招待・特別）
【INVITED】AIP Conf. Proc., ［招待講演］, ［国際会議］

Resonant Gas Oscillation with Evaporation and Condensation　　　　　　　　　　　　　　　
M. Inaba, T. Yano, M. Watanabe, K. Kobayashi
19th International Symposium on Nonlinear Acoustics, 2012年, 英語, 口頭発表（一般）
AIP Conf. Proc., No. 1474, pp.79-82, (2012)., ［国際会議］

Derivation of Nonlinear Wave Equations for Ultrasound Beam in Nonuniform Bubbly Liquids　　　　　　　　　　　　　　　
T. Kanagawa, T. Yano, J. Kawahara, K. Kobayashi, M. Watanabe, S. Fujikawa
19th International Symposium on Nonlinear Acoustics, 2012年, 英語, 口頭発表（一般）
AIP Conf. Proc., No. 1474,
pp.143-146, (2012)., ［国際会議］

Innovative Ultra-Low Environmental Load Cleaning Method Using Steam-Water Mixed Spray: II. Micro-Scale Approach　　　　　　　　　　　　　　　
M. Watanabe, K. Kobayashi, T. Sanada
6th Japanese-European Two-Phase Flow Group Meeting, 2012年, 英語, 口頭発表（一般）
Total 6 pages (CD-ROM), (2012), ［国際会議］

Innovative Ultra-Low Environmental Load Cleaning Method Using Steam-Water Mixed Spray: I. Macro-Scale Approach　　　　　　　　　　　　　　　
T. Sanada, M. Watanabe, K. Kobayashi
6th Japanese-European Two-Phase Flow Group Meeting, 2012年, 英語, 口頭発表（一般）
Total 6 pages (CD-ROM), ［国際会議］

Droplet Impact as an Elementary Process of Physical Cleaning　　　　　　　　　　　　　　　
K. Kobayashi, R. Uemura, M. Watanabe, T. Sanada, A. Hayashida
9th International Conference on Fluid Dynamics, 2012年, 英語, 口頭発表（一般）
Total 2 pages (CD-ROM), (2012)., ［国際会議］

High-Speed Droplet Impact as an Elementary Process of Physical Cleaning
Toshihide Fujikawa, Yuuki Tatekura, Kazumichi Kobayashi, Toshiyuki Sanada, Atsushi Hayashida, Masao Watanabe
ECS Transactions, 2011年10月04日, The Electrochemical Society, 英語
2011年10月04日 - 2011年10月04日, In the steam-water mixed spray-cleaning technique, droplet impact on the solid surface is the one of the primarily important physical processes. We experimentally studied a droplet impact on a solid plate that moves with a speed ranging from 1 to 50 m/s using high-speed video camera. We observed that high-speed liquid film flows radially outward along the surface just after the impact. In addition, we also observed that liquid turns into corona splash in the cases of higher impact velocities. These flows with large velocities can generate huge shear stress on the solid surface, which may contribute to cleaning. Furthermore, we numerically studied the velocity field development and found that gas flow also spreads obliquely upward. The obliquely upward flow field may also contribute in advecting removed particles or stripped resists away from the original place.

Ultrasound Beam Radiated From Circular Piston in Bubbly Liquids: Nonlinear Analysis for Envelope of Short Waves With Diffraction Effect　　　　　　　　　　　　　　　
J. Kawahara, K. Kanagawa, T. Yano, K. Kobayashi, M. Watanabe, S. Fujikawa
ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, 2011年, 英語
Paper No. AJK2011-33019, pp. 251-256 (2011)., ［国際会議］

Nonlinear Propagation of Sound Beam in Nonuniform Bubbly Liquids　　　　　　　　　　　　　　　
T. Kanagawa, J. Kawahara, T. Yano, K. Kobayashi, M. Watanabe, S. Fujikawa
ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, 2011年, 英語, 口頭発表（一般）
Paper No. AJK2011-33017, pp. 237-241 (2011)., ［国際会議］

High-Speed Droplet Impact as an Elementally Process of Physical Cleaning　　　　　　　　　　　　　　　
T. Fujikawa, Y. Tatekura, K. Kobayashi, T. Sanada, A. Hayashida, M. Watanabe
ECS Meeting, 2011年, 英語, 口頭発表（一般）
ECS Transaction, Vol.41, pp. 67-74 (2011)., ［国際会議］

Numerical Analysis of Shock-Bubble Interactions near Tissue Boundaries　　　　　　　　　　　　　　　
Kazumichi Kobayashi
6th Japan-Taiwan Workshop on Mechanical and Aerospace Engineering, 2011年, 英語, 口頭発表（一般）
Total 8 pages (CD-ROM), (2011)., ［国際会議］

Direct Numerical Simulations of Bubble Collapse near a Tissue Surface with the Ghost Fluid Method　　　　　　　　　　　　　　　
H. Takahira, K. Kobayashi
157th meeting of Acoustic Society of America, 2009年, 英語, 口頭発表（一般）
Journal of Acoustic Society of America, 124, 2712, ［国際会議］

Influence of Shock-Bubble and Bubble-Bubble Interactions on the Collapse of a Cluster of Bubbles　　　　　　　　　　　　　　　
K. Kobayashi, Y. Jinbo, H. Takahira
7th International Symposium of Cavitation (Cav2009), 2009年, 英語, 口頭発表（一般）
Total 11 pages (CD-ROM), No.53, (2009), ［国際会議］

Numerical Investigations of Interactions between Shock Waves and Bubbles near Tissue Surface Using the Ghost Fluid Method　　　　　　　　　　　　　　　
S. Syu, T. Matsuno, K. Kobayashi, H. Takahira
7th JSME-KSME Thermal and Fluid Engineering Conference, 2008年, 英語, 口頭発表（一般）
Total 2 pages (CD-ROM，No.E322), (2008), ［国際会議］

Molecular Gas Dynamics Simulations for the Collapse of Gas or Vapor Bubbles　　　　　　　　　　　　　　　
K. Kobayashi, H. Takahira
7th JSME-KSME Thermal and Fluid Engineering Conference, 2008年, 英語, 口頭発表（一般）
Total 2 pages (CD-ROM, No.E313), (2008)., ［国際会議］

Flow Structure and Bubble Fission of Gas-Liquid Two-Phase Venturi Tube Flows　　　　　　　　　　　　　　　
K. Umeyama, K. Ikema, K. Kobayashi, H. Takahira
7th JSME-KSME Thermal and Fluid Engineering Conference, 2008年, 英語, 口頭発表（一般）
Total 2 pages (CD-ROM，No.E122), (2008)., ［国際会議］

Molecular Gas Dynamics Simulation of the Collapse of Condensable Gas bubbles　　　　　　　　　　　　　　　
K. Kobayashi, H. Takahira
Cavitation in Turbo-Machinery & Medical Applications, 2008年, 英語, 口頭発表（一般）
pp.204-209(CD-ROM), (2008), ［国際会議］

Numerical Analysis of Shock-Bubble Interactions near Boundaries Using the Ghost Fluid Method　　　　　　　　　　　　　　　
K. Kobayashi, T. Matsuno, S. Syu, H. Takahira
Cavitation in Turbo-Machinery & Medical Applications, 2008年, 英語, 口頭発表（一般）
pp.190-194, (CD-ROM), (2008)., ［国際会議］

Condensation Coefficient of Water in a Weak Condensation State　　　　　　　　　　　　　　　
K. Kobayashi, S. Watanabe, D. Yamano, T. Yano, S. Fujikawa
1st International Colloquium on Dynamics, Physics and Chemistry of Bubble and Gas-Liquid Boundaries, 2007年, 英語, 口頭発表（一般）
Total 10 pages (CD-ROM), (2007)., ［国際会議］

Shock-Tube-Deduced Condensation Coefficients of Methanol and Water Vapors　　　　　　　　　　　　　　　
S. Watanabe, K. Kobayashi, M. Inaba, T. Yano, S. Fujikawa
International Symposium on Advanced Fluid/Solid Science and Technology in Experimental Mechanics, 2006年, 英語, 口頭発表（一般）
Total 5 pages (CD-ROM, No.A10-4),(2006), ［国際会議］

Molecular Gas Dynamics Approaches to Interfacial Phenomena Accompanied with Condensation　　　　　　　　　　　　　　　
S. Mikami, K. Kobayashi, T. Ota, S. Fujikawa, T. Yano, M. Ichijo
ECI International Conference on Heat Transfer and Fluid Flow in Microscale, 2005年, 英語, 口頭発表（一般）
Total 4 pages (CD-ROM, No.70), (2005), ［国際会議］

A New Approach for Determination of Condensation Coefficient of Methanol by Combining Molecular Gas Dynamics Study and Shock Tube Experiment　　　　　　　　　　　　　　　
K. Kobayashi, S. Fujikawa, T. Yano
6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics, 2005年, 英語, 口頭発表（一般）
Total 5 pages (CD-ROM, No.7-b-7), (2005)., ［国際会議］

Numerical Computations of Vapor Condensation in Vapor-Liquid Nonequilibrium State at Shock Tube Endwall　　　　　　　　　　　　　　　
K. Kobayashi, T. Yano, S. Fujikawa
5th International Conference on Multiphase Flow, 2004年, 英語, 口頭発表（一般）
Total 9 pages (CD-ROM, No.413), (2004)., ［国際会議］

Numerical Analysis of Condensation Process of a Polyatomic Vapor behind a Reflected Shock Wave Based on the Kinetic Theory of Gases　　　　　　　　　　　　　　　
K. Kobayashi, T. Yano, S. Fujikawa
15th International Symposium on Transport Phenomena, 2004年, 英語, 口頭発表（一般）
Total 5 pages (CD-ROM, No.101), (2004)., ［国際会議］

Numerical Study of Condensation of a Polyatomic Vapor by a Shock Wave Based on the Kinetic Theory of Gases　　　　　　　　　　　　　　　
T. Yano, K. Kobayashi, S. Fujikawa
4th ASME/JSME Joint Fluids Engineering Conference, 2003年, 英語, 口頭発表（一般）
Total 6 pages (CD-ROM, No. FEDSM2003-45022), (2003)., ［国際会議］

流体力学演習　　　　　　　　　　　　　　　
大坂府立大学

機械設計演習　　　　　　　　　　　　　　　
大坂府立大学

ラボラトリーセミナー　　　　　　　　　　　　　　　
北海道大学

計測工学　　　　　　　　　　　　　　　
北海道大学

テクニカルイングリッシュ　　　　　　　　　　　　　　　
北海道大学

熱流体力学演習　　　　　　　　　　　　　　　
北海道大学

応用数学演習　　　　　　　　　　　　　　　
北海道大学

分子流体力学特論　　　　　　　　　　　　　　　
北海道大学

2024年04月 - 現在
日本伝熱学会　　　　　　　　　　　　　　　

ナノ粒子分散液体の蒸発係数
科学研究費助成事業
2024年04月01日 - 2028年03月31日
小林 一道, 藤井 宏之, 渡部 正夫
日本学術振興会, 基盤研究(B), 北海道大学, 24K00797

蒸気中の液滴固体面衝突における凝縮効果によるsplash発生抑制機序の解明
科学研究費助成事業
2024年04月01日 - 2026年03月31日
渡部 正夫, 小林 一道, 藤井 宏之, 真田 俊之
日本学術振興会, 基盤研究(B), 北海道大学, 23K26027

赤外線励起による溶剤の分子内振動の緩和と溶剤乾燥に効果的な赤外線吸収波長帯の解明
科学研究費助成事業
2022年04月 - 2025年03月
戸谷 剛, 小林 一道
日本学術振興会, 基盤研究(B), 北海道大学, 研究分担者, 22H01407

間の分子流体力学
さきがけ
2021年10月 - 2025年03月
小林一道
科学技術振興機構(JST), 北海道大学, 研究代表者, JPMJPR21O3

高Oh液滴の固体面衝突直後に発生するsplashの相似則構築とメカニズム解明
科学研究費助成事業 基盤研究(B)
2020年04月01日 - 2023年03月31日
渡部 正夫, 小林 一道, 藤井 宏之, 真田 俊之
本研究の目的は，「高Oh液滴の固体面衝突直後に発生するcorona splashとprompt splashの発生条件を明らかにし，二つのsplashの発生メカニズムを説明する理論モデルを構築すること」である．この目的を達成するために，本年度は以下の２項目について研究を行った．
１．固体表面に滴衝する高Oh液滴の観察：自由落下するシリコンオイルを用いて衝突実験を行い，高Oh液滴のsplash発生条件を探索した．高粘度液滴衝突ではあるOhを閾値としてsplashとreceding break-upの２種類の不安定性が観察されること, 閾値Oh数以上ではreceding break-upのみが観察されさらにOh数を大きくすると不安定性が観察されないこと，receding break-upはある衝突速度以上では観察されないことを明らかにした．
２．粗い表面に衝突する液滴の観察：低圧力環境下の高速液滴衝突 (50m/s程度) 実現を行い，固体表面粗さの効果を検討するために，減圧チャンバ内での粗い固体表面への高速液滴衝突を観察した．平滑表面および粗い固体表面においてsplashの発生閾値を検討した．低Oh液滴衝突においては，これまで観察されていたcorona splashとprompt splashに加えて衝突直後極短時間にのみ観察されるsplashが存在することが発見され，これまでに提案されたsplash発生閾値モデルは，粗い表面には適用できないことを明らかにした．
３．高速度カラー光干渉計による気液界面計測システムによる観察：固体表面に衝突する液滴の固体面衝突直前に，固体表面と液滴との間に形成される薄空気膜はsplash発生に大きな影響を与える．この薄空気膜厚さの空間分布の時間変化が，固体表面電位と液体の誘電率によって大きく変化することを明らかにした．
日本学術振興会, 基盤研究(B), 北海道大学, 20H02061

高密度なコロイド溶液におけるふく射の干渉効果とふく射輸送に及ぼす影響の解明
科学研究費助成事業 基盤研究(B)
2020年04月01日 - 2023年03月31日
藤井 宏之, 西村 吾朗, 渡部 正夫, 小林 一道
本研究の目的は、「生体を模擬した高密度なコロイド溶液に対して、輻射（ふくしゃ）の干渉効果を組み込んだ輻射輸送モデル(輸送モデル)を新たに構築した上で、干渉効果が及ぼす光伝播への影響を明らかにすること」である。生体光イメージングや光治療において、生体内の光伝播を定量的に把握することが必要であり、光を輻射と捉えた輸送モデルが活用されている。しかし、従来の輸送モデルには、生体のような高密度な散乱媒体において重要となる干渉効果が考慮されていない。本研究では電磁波の散乱理論より干渉効果を考慮した散乱特性を計算し、輸送モデルに組み込んだ上で光強度の時間分解波形を数値計算する。また、短パルスレーザー光源による光強度計測も実施する。干渉効果が光伝播へ影響を及ぼす時空間スケールについて、散乱係数などで表される無次元数を用いて解析し、理論、数値計算、実験より体系的に明らかにする。この目的を達成するため、本年度は以下の３項目について研究を実施した。
１．光散乱特性を簡潔に記述するモデル式を開発した。モデル式により、単一散乱の寄与と干渉効果の寄与を分離して評価することに初めて成功した。
２．分担研究者の西村吾朗助教の波長可変の光計測システムを利用して、コロイド溶液（脂質エマルジョン）において、濃度20%まで21条件、720 nmから860 nmまでの6条件で光計測を実施した。光計測データを逆解析することで算出した光学特性値をモデル式より解析し、干渉効果の波長依存性を明らかにした。
３．分子動力学シミュレーションにより構造特性を計算し、干渉散乱理論に組み込んで散乱特性を計算した。粒子間の引力相互作用が散乱特性に強く影響を及ぼすことを明らかにした。
日本学術振興会, 基盤研究(B), 北海道大学, 20H02076

混合気体に接した非平衡気液界面相変化機序の解明と分子混相流体力学への展開
科学研究費助成事業 基盤研究(C)
2020年04月 - 2023年03月
小林 一道
本提案研究は，混合気体に接した気液界面における気体論境界条件を構築し，様々な分野に本研究成果を展開することである．2021年度は主に以下の３つの研究を行った．
１．分子計算（分子運動論および分子動力学シミュレーション）を用いて，非平衡気液界面における気体論境界条件の構築を行った．その結果，気体論境界条件に含まれる二つの未知パラメータ（蒸発係数および凝縮係数）を決定した．本結果より，非平衡気液界面における蒸発係数と凝縮係数の値は，平衡状態および非平衡状態においてほぼ変わらないことが明らかとなった．これにより，初期液体温度などの条件にもよるが，平衡状態の蒸発係数および凝縮係数を求めておけば気体論境界条件を構築できることが示唆された．
２．分子動力学解析を用いて，固体壁と液体に挟まれた気体のクエット流れについて解析を行った．この研究より，気液界面における気体論境界条件の位置を検証した．本研究より，１の研究で指定していた気体論境界条件の位置は妥当であることが示唆された．また，高クヌーセン数流れになるほど，気液界面の境界条件が平衡状態の関数形から異なることが示唆された．これについてはさらなる検討が必要である．
３．分子動力学解析を用いて，混合液体（エタノール・イソオクタン）の蒸発について検証した．分子動力学計算を用いてエタノール・イソオクタンの気液平衡系を作り出し，１の研究で提案した方法によって，液体から蒸発する分子の成分について調べた．その結果，エタノールの濃度が低い混合液体においても，蒸発するエタノール分子の割合は高くなることが示された．今後はこの知見を用いて実験結果を整理する予定である．
日本学術振興会, 基盤研究(C), 北海道大学, 20K04277

赤外線連続照射による気液界面での分子内振動の緩和と溶剤乾燥に効果的な吸収帯の解明
科学研究費補助金
2019年04月 - 2022年03月
戸谷剛, 小林一道
日本学術振興会, 競争的資金

細い穴の中における気体分子の振る舞い (2)　　　　　　　　　　　　　　　
共同研究
2020年07月
企業, 北海道大学, 研究代表者, 産学連携による資金

細い穴の中における気体分子の振る舞い (1)　　　　　　　　　　　　　　　
共同研究
2019年12月 - 2020年06月
企業, 北海道大学, 研究代表者, 産学連携による資金

表面プラズモン共鳴観察によるアクティブマターのメカニズムの解明
科学研究費補助金
2018年04月 - 2020年03月
渡部正夫
日本学術振興会, 競争的資金

高速射出液膜流れの固気液三相接触線近傍流れ場の不安定現象に及ぼす周囲気体効果
科学研究費補助金
2017年04月 - 2020年03月
渡部正夫
日本学術振興会, 競争的資金

超音波と微細気泡を用いた混合液体分離技術の開発　　　　　　　　　　　　　　　
公益信託小野音響学研究助成基金
2019年04月 - 2019年12月
小林一道
公益信託小野音響学研究助成基金, 研究代表者, 競争的資金

2成分混合気体の気体論境界条件の決定とその応用
科学研究費補助金
2016年04月 - 2019年03月
小林一道
日本学術振興会, 研究代表者, 競争的資金

蒸気中における液滴固体面衝突後に発達する高速液膜流れ不安定性現象に及ぼす凝縮効果
科学研究費助成事業
2014年04月01日 - 2017年03月31日
渡部 正夫, 真田 俊之, 小林 一道, 矢口 久雄, 藤井 宏之
固体表面への液滴衝突は噴霧冷却，インクジェット印刷，超清浄洗浄等の技術応用において重要な技術的要素である．本研究では，Xuら（Phys. Rev. Lett, 184505, 2005）の液滴衝突後に発生する高速液膜の不安定現象発生閾圧力についてのモデルが，周囲気体温度の寄与を予測することが可能であることを示した．さらに周囲気体が凝縮性気体の場合には，高速液膜の不安定現象発生閾圧力がXuらのモデルでは予測できず，不安定現象発生閾圧力はより高く，すなわち安定化することを示した．
日本学術振興会, 基盤研究(B), 北海道大学, 26289031

平均場運動論理論による高速移動気液界面における非定常熱・物質輸送現象の解明
科学研究費補助金
2014年04月 - 2016年03月
渡部正夫
日本学術振興会, 競争的資金

気体分子運動論による気液二相流体の高精度計算手法の構築と界面ダイナミクスへの展開
科学研究費補助金
2013年04月 - 2016年03月
小林一道
日本学術振興会, 研究代表者, 競争的資金

集束超音波と液面の相互作用による液体ジェット生成技術の開発　　　　　　　　　　　　　　　
若手研究人材育成事業
2015年04月 - 2016年02月
小林一道
ノーステック財団研究開発助成事業, 研究代表者, 競争的資金

マイクロヒートポンプ内の相変化を伴う気液二流体流れの基礎研究　　　　　　　　　　　　　　　
北海道ガス大学助成制度
2013年04月 - 2014年03月
小林一道
北海道ガス, 研究代表者, 競争的資金

分子速度分布関数と平均場運動論理論による超臨界混合界面における輸送現象
科学研究費補助金
2011年04月 - 2013年03月
渡部正夫
液体燃料ロケットエンジンの信頼陸の向上のために,燃料混合気の濃度分布の高精度予測のための,気液混合界面での輸送現象の解明を目的としている.相変化が存在する気液界面における輸送現象を評価するために,平均場運動論理論から得られるEnskog-Vlasov方程式を用いることにより,界面の物理特陸を評価するために数値解析手法を解析し,分子動力学シミュレーション結果と比較することにより,混合界面での熱・物質輸送現象を検討する.
日本学術振興会, 挑戦的萌芽研究, 北海道大学, 競争的資金, 23656122

気液相変化を伴う界面境界条件の構築およびその流体力学への応用
科学研究費補助金
2010年04月 - 2013年03月
小林一道
気体－液体界面における素過程を考慮し，分子動力学や気体分子論の立場から流体体力学へ応用可能な境界条件のモデルを導出し流体力学シミュレーションへの応用を目指す．
日本学術振興会, 研究代表者, 競争的資金

単一液滴の抵抗低減に及ぼす周囲蒸気凝縮効果の考究による革新的洗浄法素過程の解明
科学研究費補助金
2010年04月 - 2013年03月
渡部 正夫
日本学術振興会, 競争的資金

気泡崩壊現象における極限物理の解明
科学研究費補助金
2009年04月 - 2013年03月
高比良 裕之
日本学術振興会, 競争的資金

異なる三つの法則が支配する非平衡気液界面の分子輸送過程に関するマルチスケール展開
科学研究費補助金
2009年04月 - 2011年03月
藤川 重雄
日本学術振興会, 競争的資金

革新的洗浄方法原理解明のための水蒸気・水混相噴流衝突速度における凝縮効果の解析
科学研究費補助金
2009年04月 - 2011年03月
渡部 正夫
日本学術振興会, 競争的資金

分子動力学・分子気体力学による蒸発・凝縮係数の決定と新しい気泡力学への展開
科学研究費補助金
2007年04月 - 2009年03月
小林一道
分子動力学および分子気体力学を用いて気液界面での蒸発・凝縮メカニズムの分子論的解明を行う。また、前述の研究から得られた知見を用いて気液界面で蒸発・凝縮現象を伴う気泡のダイナミクスに関する研究を行う．
日本学術振興会, 若手研究(スタートアップ), 大阪府立大学, 研究代表者, 競争的資金, 19860063

分子気体力学解析と衝撃波管の実験による非平衡状態における気体論境界条件の確立
特別研究員奨励費
2006年04月 - 2007年03月
小林一道
日本学術振興会, 研究代表者, 競争的資金

Evaporation/Condensation Phenomena, Numerical Simulation of Kinetic Theory of Gases, Molecular Dynamics　　　　　　　　　　　　　　　
競争的資金