Kobayashi Kazumichi(Faculty of Engineering　Mechanical and Aerospace Engineering　Thermal and Fluid Systems)｜ Hokkaido University Researchers (Hokkaido University Researchers Directory)

Name

AuthorName

Position

Affiliation

Research Field

Kobayashi Kazumichi

Faculty of Engineering　Mechanical and Aerospace Engineering　Thermal and Fluid Systems	Associate Professor
Institute for the Advancement of Higher Education	Associate Professor

Last Updated :2026/01/15

■Researcher basic information

Research Keyword

Molecular dynamics

Kinetic theory of gases

Droplet

Bubble

Interface

分子流体力学

Fluid Mechanics

Research Field

Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Fluid engineering

Educational Organization

Bachelor's degree program, School of Engineering

Master's degree program, Graduate School of Engineering

Doctoral (PhD) degree program, Graduate School of Engineering

■Career

Career

Apr. 2013 - Present
Hokkaido University, Faculty of Engineering, Associate Professor

Apr. 2015 - Sep. 2015
Nagoya University, Graduate School of Engineering, Part-time lecturer

Apr. 2010 - Mar. 2013
Hokkaido University, Faculty of Engineering, Assistant Professor

Apr. 2007 - Mar. 2010
Osaka Prefecture University, Assistant Professor

Apr. 2006 - Mar. 2007
Hokkaido University, Graduate school of Engineering, JPSP Fellowship Researcher

Educational Background

Apr. 2004 - Mar. 2007, Hokkaido University, 大学院工学研究科, Division of Mechanical Science, Japan

Apr. 2002 - Mar. 2004, Hokkaido University, Graduate school of Engineering, 機械科学専攻修士課程

Apr. 1998 - Mar. 2002, Hokkaido University, School of Engineering, Department of Mechanical Engineering, Japan

Committee Memberships

Apr. 2025 - Present
Heat Transfer Society of Japan, delegate, Society

Apr. 2024 - Present
The Japanese Society of Fluid Mechanics, Representative committee member, Society

Apr. 2018 - Present
日本機械学会, 日本機械学会論文集編修委員会アソシエイトエディタ, Society

Jun. 2025 - May 2026
Heat Transfer Society of Japan, Comitte of annual meeting, Society

Sep. 2024 - Sep. 2025
The Japan Society of Mechanical Engineers, Comittie of annual meeting, Society

Jan. 2024 - Jan. 2025
Japanese society of thermophysical properties, councillor, Society

Apr. 2023 - Mar. 2024
Japanese Society of Mechanical Engineering, Executive Committee, Society

Apr. 2022 - Mar. 2024
The Japan Society of Mechanical Engineering, Secretary, Technical Committee, Fluid Engineering Division, Society

Apr. 2023 - Aug. 2023
The Japanese Society for Multiphase Flow, Comittee of symposium of multiphase flow, Society

Apr. 2020 - Mar. 2022
The Japan Society of Fluid Mechanics, Delegate, Society

Jan. 2021 - Jan. 2022
第53回日本熱物性シンポジウム実行委員会, 幹事, Society

Jan. 2020 - Jan. 2022
Japanese Society of Thermophysical Properties, Councillor, Society

Apr. 2018 - Mar. 2020
日本機械学会RC277分科会, 幹事, Society

Dec. 2018 - Nov. 2019
第33回数値流体力学シンポジウム, 実行委員, Society

Aug. 2018 - Aug. 2019
日本混相流学会, 評議員, Society

Aug. 2017 - Aug. 2019
日本混相流学会, ICeM委員, Society

Aug. 2016 - Aug. 2019
日本混相流学会, 編集委員, Society

Apr. 2018 - Mar. 2019
日本機械学会流体工学部門, 広報委員会, Society

Nov. 2017 - Dec. 2018
第16回流れの夢コンテスト, 実行委員長, Society

Nov. 2017 - Nov. 2018
日本機械学会第96期流体工学部門講演会, 実行委員, Society

Oct. 2017 - Oct. 2018
第19回キャビテーションに関するシンポジウム, 幹事, Society

Oct. 2017 - May 2018
第55回伝熱シンポジウム, 実行委員（プログラム＆OS担当）, Society

Jan. 2016 - Jan. 2018
日本熱物性学会, 評議員, Society

Apr. 2015 - Mar. 2017
日本機械学会, P-SCC13:マイクロ熱流動に関する調査研究分科会委員, Society

Apr. 2014 - Mar. 2017
日本機械学会, 校閲委員, Society

Apr. 2015 - Mar. 2016
日本機械学会北海道支部, 商議員（支部会計委員兼務）, Society

Apr. 2014 - Sep. 2015
日本機械学会, 日本機械学会2015度年次大会実行委員, Society

Jul. 2014 - Mar. 2015
日本機械学会, 日本機械学会北海道支部学生委員, Society

Sep. 2013 - Jul. 2014
日本混相流学会, 混相流シンポジウム2014 実行委員総務, Society

Jan. 2012 - Jan. 2014
日本熱物性学会, 評議員, Society

Apr. 2011 - Mar. 2013
日本機械学会北海道支部, 流体工学懇話会幹事, Society

Apr. 2011 - Mar. 2013
日本機械学会流体工学部門, 広報委員, Society

Apr. 2010 - Sep. 2010
日本流体力学会, 日本流体力学会年会2010 Web幹事, Society

■Research activity information

Awards

Jul. 2023, Fluids Engineering DIvision, the Japan Society of Mechanical Engineers, Frontier Award
Molecular Fluid Dynamics Analysis of Heat and Mass Transport at Gas-Liquid Interface
Kazumichi Kobayashi, 33844587

Apr. 2021, 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

Apr. 2008, Japanese Society of Mechanical Engineering, JSME Medal for Outstanding Pape　　　　　　　　　　　　　　　
Molecular Gas Dynamics of Condensation Processes of Methanol Vapor behind a Reflected Shock Wave in a Shock Tube
Japan

Mar. 2007, Japanese Society of Thermophysical Properties, Best Presentation Award　　　　　　　　　　　　　　　
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
Kazumichi Kobayashi

Jun. 2005, 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

Papers

Relaxation enhancement from intra- to intermolecular vibrations in water continuously excited by wavelength-selective infrared radiation
Yoshitaka TANADA, Tsuyoshi TOTANI, Satoru ODASHIMA, Kazumichi KOBAYASHI, Yoshio KONDO
Journal of Thermal Science and Technology, Japan Society of Mechanical Engineers, Sep. 2025, [Peer-reviewed], [Invited]
English, Scientific journal

Minimum thickness of liquid film for the validity of water hammer theory
Kazumichi Kobayashi, Jotaro Akazawa, Kotaro Ohashi, Mikihiro Muramatsu, Takuro Nagakawa, Hiroyuki Fujii, Masao Watanabe
Physics of Fluids, 37, 8, AIP Publishing, 01 Aug. 2025, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, Systems that clean by high-speed nanodroplet injection have recently been developed; however, elucidating the cleaning mechanism underlying nanodroplet impact is urgently required. In this study, numerical simulations of the high-speed impact phenomenon of two liquid films were performed using the Enskog–Vlasov direct simulation Monte Carlo method. We determine the minimum liquid film thickness for which the water hammer theory is applicable to the maximum pressure generated during liquid film impact. The simulation results show that the water hammer pressure was generated when the liquid film thickness exceeded the compression wavefront thickness generated by the liquid film impact, which is more than ten times the molecular diameter., 50159585

Polydisperse stickiness and particle size on light scattering in dense colloidal suspensions: A numerical study using the binary sticky hard-sphere model
Hiroyuki Fujii, Koyata Nishikawa, Hyeonwoo Na, Kazumichi Kobayashi, Masao Watanabe
Results in Physics, 73, 108247, 108247, Elsevier BV, Jun. 2025
Scientific journal

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, Aug. 2024
Scientific journal

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, 22 May 2024
Scientific journal, 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, 01 Aug. 2023, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 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, Aug. 2023
Scientific journal

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, Mar. 2023, [Peer-reviewed], [Corresponding author]
English, Scientific journal, 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, Jul. 2022, [Peer-reviewed], [Corresponding author]
English, Scientific journal, 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, Jun. 2022, [Peer-reviewed]
English, Scientific journal, 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, Jun. 2022, [Peer-reviewed]
English, Scientific journal

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, 01 Jun. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, 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, 31 Jan. 2022, [Peer-reviewed]
English, Scientific journal

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, 24 Jan. 2022, [Peer-reviewed]
English, Scientific journal, 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, 22 Dec. 2021, [Peer-reviewed], [Corresponding author], [International Magazine]
English, Scientific journal, 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), 16 Mar. 2021, [Peer-reviewed]
English, Scientific journal, 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, Sep. 2020, [Peer-reviewed]
English, Scientific journal

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, 10 Jul. 2020, [Peer-reviewed]
Scientific journal

Evaporation coefficient and condensation coefficient of vapor under high gas pressure conditions
Kotaro Ohashi, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
Scientific Reports, 10, 8143, May 2020, [Peer-reviewed], [Corresponding author]
English, Scientific journal

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, Apr. 2020, [Peer-reviewed]
English, Scientific journal

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), 15 Jan. 2020, [Peer-reviewed]
English, Scientific journal

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, [Peer-reviewed]
English

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, Jun. 2019, [Peer-reviewed]
English, Scientific journal

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, Apr. 2019, [Peer-reviewed]
English, Scientific journal

Molecular gas dynamics analysis on condensation coefficient of vapour during gas-vapour bubble collapse
Kazumichi Kazumichi Kobayashi, Takahiro Nagayama, Masao Watanabe, Hiroyuki Fujii, Misaki Kon
Journal of Fluid Mechanics, 856, 1045, 1063, Dec. 2018, [Peer-reviewed]
English, Scientific journal

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, Dec. 2018, [Peer-reviewed]
English, Scientific journal

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, Jul. 2018, [Peer-reviewed]
English, Scientific journal

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, 01 Apr. 2018, [Peer-reviewed]
English, Scientific journal

Fine droplets generation induced by interactions between focused ultrasound and a liquid surface
Kazuya Seko, Kazumichi Kobayashi, Hiroyuki Fujii, Masao Watanabe
Japanese Journal of Multiphase Flow, 32, 1, 59, 64, 2018, [Peer-reviewed], [Invited]
Japanese

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, Jul. 2017, [Peer-reviewed], [Invited]
English, Scientific journal

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, May 2017, [Peer-reviewed]
English, Scientific journal

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, Mar. 2017, [Peer-reviewed]
English, Scientific journal

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, Sep. 2016, [Peer-reviewed]
English, Scientific journal

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, Aug. 2016, [Peer-reviewed]
English, Scientific journal

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, Mar. 2016, [Peer-reviewed]
English, Scientific journal

Estimation of evaporation mass flux at vapor-liquid interface during nonequilibrium evaporation/condensation
Misaki Kon, Kazuichi Kobayashi, Kiyofumi Sasaki, Masao Watanabe
Japanese Journal of Multiphse flow, 29, 5, 493, 500, THE JAPANESE SOCIETY FOR MULTIPHASE FLOW, Mar. 2016, [Peer-reviewed], [Invited]
Japanese, Scientific journal, 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, 03 Dec. 2015, [Peer-reviewed]
English, Scientific journal

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, 03 Dec. 2015, [Peer-reviewed]
English, Scientific journal

How do bubbles reduce the speed of sound in a bubbly liquid in a duct?
Kazumichi KobayashiJunya Kawahara, Masao Watanabe, Kazumichi Kobayashi
Mechanical Engineering Letters, 1, 115-00464, 15-00464, Dec. 2015, [Peer-reviewed]
English, Scientific journal

Liquid film flow generated by high-speed droplet impact in low-pressure enviroment
Masaya Kato, Masao Watanabe, Kazumichi Kobayashi, Toshiyuki Sanada
Japanese Journal of Multiphase Flow, 28, 5, 531, 536, Mar. 2015, [Peer-reviewed], [Invited]
Japanese, Scientific journal

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, [Peer-reviewed]
English, International conference proceedings

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, 2015, [Peer-reviewed]
English, Scientific journal

Method of determining kinetic boundary conditions in net evaporation/condensation
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
PHYSICS OF FLUIDS, 26, 7, 072003, Jul. 2014, [Peer-reviewed]
English, Scientific journal

Evaporation and Condensation Coefficients of Methanol at Room Temperature, and Consideration of Kinetic Boundary Condition
Kazumichi Kobayashi, Shingo Mouri, Yusuke Watanabe, Masao Watanabe, Shigeo Fujikawa
Netsu Bussei, 27, 1, 9, 14, JAPAN SOCIETY OF THERMOPHYSICAL PROPERTIES, Jan. 2013, [Peer-reviewed]
Japanese, Scientific journal, The growth rate of a liquid film formed on a shock-tube endwall due to condensation of methanol vapor behind a shock wave reflected at the endwall is measured by an optical interferometer at room temperature, and it is analyzed with the aid of molecular gas dynamics in order to deduce evaporation and condensation coefficients. The measurements are done in the region of 1 ≤σ / ρ*<1.3, where σ / ρ* is nonequilibrium degree. The condensation coefficient is almost the same value as the evaporation coefficient (=0.86) in 1 ≤σ / ρ* <1.05 and decreases to the smaller values than the evaporation coefficient in σ / ρ*＞1.05, and the kinetic boundary condition is valid in 1 ≤σ / ρ*<1.05.

蒸発・凝縮をともなう非線形共鳴音波
INABA MASASHI, YANO TAKERU, KOBAYASHI KAZUMICHI, WATANABE MASAO
ながれ, 31, 6, 487, 490, 日本流体力学会, 25 Dec. 2012
Japanese

Thin Film Removal by Steam and Water Mixed Spray (Removal Characteristic of Deposited Aluminum Film and Effects of Surface Temperature Change)
Toshiyuki Sanada, Kentaro Hashimoto, Shouji Hayashida, Kazumichi Kobayashi, Masao Watanabe
Konsoryu, 26, 2, 172, 177, THE JAPANESE SOCIETY FOR MULTIPHASE FLOW, 2012, [Peer-reviewed]
Japanese, Scientific journal, 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.

Observation of Deformation of Single Droplet Impact on Solid Surface (Effects of Liquid Properties, Surface Roughness and Surrounding Gas Pressure)
Yasutaka Sakurai, Kazumichi Kobayashi, Toshihide Fujikawa, Toshiyuki Sanada, Masao Watanabe
Konsoryu, 26, 2, 164, 171, 2012, [Peer-reviewed]
Japanese, Scientific journal

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, 04 Oct. 2011, [Peer-reviewed]
English, Scientific journal

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, Oct. 2011, [Peer-reviewed]
English, Scientific journal

Behavior of Phospholipid Layer-Coated Microbubbles under Pressure Change
Yuki Tanaka, Kazumichi Kobayashi, Hiroyuki Takahira
Japanese Journal of Multiphase Flow, 24, 5, 559, 566, 日本混相流学会, Mar. 2011, [Peer-reviewed], [Invited]
Japanese, Scientific journal

Application of Multigrid Ghost Fluid Method to the Interaction of ShockWaves with Bubbles in Liquids
Kazumichi Kobayashi, Yoshinori Jinbo, Hiroyuki Takahira
Transactions of the Japan Society of Mechanical Engineers, Series B, 77, 773, 20, 32, Jan. 2011, [Peer-reviewed]
Japanese

Boundary element analysis of bubble dynamics under a floating body (2nd report, approximation method with spherical bubble model)
Yoshinori Jinbo, Hiroyuki Takahira, Kazumichi Kobayashi, Akihiro Yasuda
Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, 76, 762, 230, 238, Japan Society of Mechanical Engineers, 2010, [Peer-reviewed]
Japanese, Scientific journal

Boundary element analysis of bubble dynamics under a floating body (1st report, numerical simulation using the three-dimensional boundary element method with linear elements)
Yoshinori Jinbo, Hiroyuki Takahira, Kazumichi Kobayashi, Akihiro Yasuda
Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, 76, 762, 219, 229, Japan Society of Mechanical Engineers, 2010, [Peer-reviewed]
Japanese, Scientific journal

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., 05 Nov. 2009
English, In book

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, 01 Jun. 2009, [Peer-reviewed]
English, Scientific journal

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, Jul. 2008, [Peer-reviewed]
English, Scientific journal

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, Aug. 2006, [Peer-reviewed]
English, Scientific journal

Molecular gas dynamics of condensation processes of methanol vapor behind a reflected shock wave in a shock tube
Takeru Yano, Kazumichi Kobayashi, Shigeo Fujikawa
Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, 71, 702, 428, 435, Japan Society of Mechanical Engineers, 2005, [Peer-reviewed]
Japanese, Scientific journal

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, Jul. 2004, [Peer-reviewed]
English, Scientific journal

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
English, International conference proceedings

Other Activities and Achievements

Numerical Modelling of Initial Photoacoustic Pressure in Colloidal Suspensions for Photoacoustic Imaging
Hiroyuki Fujii, Toshiaki Aoki, Yuki Inoue, Iori Terabayashi, Kazumichi Kobayashi, Masao Watanabe, Technical digest of 26th Microoptics Conference (MOC2021), PO-11, 164, 165, Sep. 2021, [Peer-reviewed]
The Japan Society of Applied Physics, English

Finite element investigation of light propagationin the human neck using the time-dependent radiative transfer theory
Shigeki Endo, Hiroyuki Fujii, Kazumichi Kobayashi, Masao Watanabe, Proceeding of the 7th Asian NIR symposium (ANS2020), 2020, NRT-0008, 60, 61, Feb. 2020, [Peer-reviewed]
English

Numerical study on light propagation in a white bread loaf
Hiroyuki Fujii, Goro Nishimura, Shigeki Endo, Koki Nomura, Kazumichi Kobayashi, Masao Watanabe, Proceeding of the 7th Asian NIR symposium (ANS2020), 2020, AFI-0007, 14, 15, Feb. 2020, [Peer-reviewed], [International Magazine]
English

Numerical treatment of highly forward scattering on radiative transfer using the delta-M approximation and Galerkin quadrature method
Hiroyuki Fujii, Go Chiba, Yukio Yamada, Yoko Hoshi, Kazumichi Kobayashi, Masao Watanabe, Proceedings of the 9th International Symposium on Radiative Transfer, RAD-19, SM05, 261, 268, Sep. 2019, [Peer-reviewed]
English

Numerical errors of light propagation in the two-dimensional human neck model using the time-dependent radiative transfer equation with renormalized phase functions
Hiroyuki Fujii, Yamada Yukio, Hoshi Yoko, Kobayashi Kazumichi, Watanabe Masao, AIP Conference Proceedings (ICNAAM2018), 2116, 450037, 1, 4, Jul. 2019, [Peer-reviewed]
English

Finite element investigation of a void region on light propagation in scattering media using the radiative transfer equation
Kosuke Tabayashi, Hiroyuki Fujii, Kazumichi Kobayashi, Masao Watanabe, AIP Conference Proceedings (ICNAAM2018), 2116, 450052, 1, 4, Jul. 2019, [Peer-reviewed]
English

Light propagation models of the human neck for photoacoustic imaging of thyroid cancer
Kosuke Tabayashi, Hiroyuki Fujii, Shinpei Okawa, Kazumichi Kobayashi, Yukio Yamada, Yoko Hoshi, Masao Watanabe, CMBE Proceedings (6th International Conference on Computational & Mathematical Biomedical Engineering), A5, 161, 164, May 2019, [Peer-reviewed]
English

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, May 2019, [Peer-reviewed]
Japanese, Summary national conference

単一液滴衝突時に取り込まれる空気膜の観察
Riichiro Endo, Masao Watanabe, Kazumichi Kobayashi, Hiroyuki Fujii, 流体工学部門講演会講演論文集, 2018, OS2-5, May 2019, [Peer-reviewed]
Japanese, Summary national conference

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, Apr. 2019, [Peer-reviewed], [Lead author, Corresponding author]
English

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, [Peer-reviewed]

Numerical study of light scattering in the human neck for diagnosis of thyroid cancers by optical tomography
Fujii Hiroyuki, Yamada Yukio, Hoshi Yoko, Kobayashi Kazumichi, Watanabe Masao, Extended abstract of the 12th CME International Conference, OS12, 2, 2018
English, Summary international conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
English

Numerical investigation of light and pressure propagation in biological tissue for model-based photoacoustic tomography　　　　　　　　　　　　　　　
Kosuke Tabayashi, Hiroyuki Fujii, Kazumichi Kobayashi, Masao Watanabe, Extended Abstracts of The 9th JSME-KSME Thermal and Fluids Engineering Conference, TFEC9-1526, 1, 4, Oct. 2017, [Peer-reviewed]
English

Influence of condensation coefficient on spherical bubble collapse with evaporation and condensation
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, Apr. 2017
日本流体力学会, Japanese

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
English, Summary international conference

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
Japanese, Summary national conference

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

Laboratory of Fluid Dynamics, Division of Mechanical and Space Engineering, Faculty of Engineering, Hokkaido University
渡部正夫, 小林一道, 藤井宏之, 混相流 = Japanese journal of multiphase flow, 30, 4, 408, 411, Dec. 2016
日本混相流学会, Japanese

Near-infrared optical properties of white bread using the light propagation model
Hiroyuki Fujii, Goro Nishimura, Kiyohito Hattori, Kazumichi Kobayashi, Masao Watanabe, Proceeding of the fifth Asian NIR symposium (ANS2016), 2016, P-86, 288, 289, 2016, [Peer-reviewed]
English

Quantitative method to determine the optical properties of melons by the photon diffusion equation
Kiyohito Hattori, Goro Nishimura, Hiroyuki Fujii, Kazumichi Kobayashi, Masao Watanabe, Proceeding of the fifth Asian NIR symposium (ANS2016), 2016, O-6, 72, 73, 2016, [Peer-reviewed]
English

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

J0540204 Numerical simulation of gas shear flow between liquid slab and solid wall by using Enskog-Vlasov equation
KON Misaki, KOBAYASHI Kazumichi, WATANABE Masao, Mechanical Engineering Congress, Japan, 2015, "J0540204, 1"-"J0540204-3", 13 Sep. 2015
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., The Japan Society of Mechanical Engineers, Japanese

J0540301 Numerical Computation of a Mathematical Model Applying Boundary Conditions Derived from Molecular Gas Dynamics at Gas-Liquid Interface for Describing Bubble Behaviors Accompanied by Phase Changes
MORIKAWA Shotaro, JINBO Yoshinori, TATEKURA Yuki, KOBAYASHI Kazumichi, WATANABE Masao, Mechanical Engineering Congress, Japan, 2015, "J0540301, 1"-"J0540301-5", 13 Sep. 2015
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., The Japan Society of Mechanical Engineers, Japanese

22aAK-12 Effect of nonequilibrium velocity distribution function to vapor flows
Kon M., Kobayashi K., Watanabe M., Meeting Abstracts of the Physical Society of Japan, 70, 2975, 2975, 2015
The Physical Society of Japan (JPS), Japanese

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
Japanese, Summary national conference

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
Japanese, Summary national conference

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
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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, [Peer-reviewed]
Japanese, Summary national conference

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
Japanese, Summary national conference

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, [Peer-reviewed]
English

Chapter 5 : Shock Tube Experiment of Evaporation and Condensation
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, Dec. 2014
日本流体力学会, Japanese

Report of JSMF Symposium on Multiphase Flow 2014
村井祐一, 小林一道, 混相流, 28, 4, 483, 486, Dec. 2014
日本混相流学会, Japanese

Chapter 4 Application of Molecular Gas Dynamics to Evaporation and Condensation
Kazumichi Kobayashi, Shigeo Fujikawa, 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, 25 Oct. 2014
日本流体力学会, Japanese

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

J053025 Numerical Simulation for Kinetic Boundary Condition at a Vapor-Liquid Interface Based Enskog-Vlasov Equation
KOBAYASHI Kazumichi, KON Misaki, OHASHI Kotaro, WATANABE Masao, Mechanical Engineering Congress, Japan, 2013, "J053025, 1"-"J053025-4", 08 Sep. 2013
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., The Japan Society of Mechanical Engineers, Japanese

J053024 Molecular dynamics analysis on evaporation of argon liquid in argon-neon system
HORI Kazumasa, YAHAGI Takato, TAKEUCHI Shinnosuke, YAGUCHI Hisao, KOBAYASHI Kazumichi, WATANABE Masao, Mechanical Engineering Congress, Japan, 2013, "J053024, 1"-"J053024-5", 08 Sep. 2013
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., The Japan Society of Mechanical Engineers, Japanese

Numerical analysis of nonequilibrium evaporation/condensation phenomena by Enskog-Vlasov equation
Kon Misaki, Kobayashi Kazumichi, Watanabe Masao, Meeting abstracts of the Physical Society of Japan, 68, 2, 248, 248, 26 Aug. 2013
The Physical Society of Japan (JPS), Japanese

Analysis of Discrete Model of Spherical Bubbles with Interaction : Acoustic Characteristics of Bubbly Liquids (Mathematical theory, modeling, and applications of nonlinear wave research)
KAWAHARA Junya, KOBAYASHI Kazumichi, WATANABE Masao, RIMS Kokyuroku, 1847, 10, 15, Aug. 2013
京都大学, Japanese

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, [Peer-reviewed]

304 Numerical analysis of high-speed droplet spray flow in cleaning nozzle
Tamura Toshiyuki, Kawahara Junya, Kobayashi Kazumichi, Watanab Masao, 北海道支部講演会講演概要集, 2012, 51, 83, 84, 20 Oct. 2012
The Japan Society of Mechanical Engineers, Japanese

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, [Peer-reviewed]
English

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
English

Kinetic Theory for Flow Phenomena Accompanied with Evaporation/Condensation at a Vapor-Liquid Interface
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
応用物理学会, Japanese

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

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, [Peer-reviewed]
English

J054032 Molecular Gas Dynamics on Resonant Gas Oscillations Accompanied with Phase Changes at Vapor-Liquid Interface
INABA Masashi, YANO Takeru, WATANABE Masao, KOBAYASHI Kazumichi, FUJIKAWA Shigeo, Mechanical Engineering Congress, Japan, 2011, "J054032, 1"-"J054032-2", 11 Sep. 2011
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., The Japan Society of Mechanical Engineers, Japanese

J054031 Measurements of the Evaporation Coefficient of Water Using Sound Resonance Method
NAKAMURA Shigeto, YANO Takeru, KOBAYASHI Kazumichi, WATANABE Masao, FUJIKAWA Shigeo, Mechanical Engineering Congress, Japan, 2011, "J054031, 1"-"J054031-4", 11 Sep. 2011
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., The Japan Society of Mechanical Engineers, Japanese

J054033 Numerical Simulations for Couette flows in Dense Gas Based on Enskog Equation
KOBAYASHI Kazumichi, OHASHI Kotarou, INABA Masashi, WATANABE Masao, FUJIKAWA Shigeo, Mechanical Engineering Congress, Japan, 2011, "J054033, 1"-"J054033-5", 11 Sep. 2011
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., The Japan Society of Mechanical Engineers, Japanese

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, [Peer-reviewed]
Japanese

403 Human Nailfold Capillary Shape Analysis and Red Blood Cell Velocity Measurement
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, 07 Nov. 2010
The Japan Society of Mechanical Engineers, Japanese

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, 23 Sep. 2010
一般社団法人日本機械学会, Japanese

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, 23 Sep. 2010
一般社団法人日本機械学会, Japanese

1016 Numerical Analysis for Bubble Collapse near a Gelatin Surface Using Multi-Grid Ghost Fluid Method
JINBO Yoshinori, SYU Sei, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2010, 85, "10, 16", 16 Mar. 2010
The Japan Society of Mechanical Engineers, Japanese

1020 Influence of Bubble-Bubble lnteradiononthe Propagation of Pressure Waves in Gas-Liquid Two-Phase Flows
SAYOU Akihito, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2010, 85, "10, 26", 16 Mar. 2010
The Japan Society of Mechanical Engineers, Japanese

1023 Bubble Deformation and Formation of Liquid Jet in Gas-Liquid Two-Phase Venturi Flow
KOBAYASHI Kazumichi, UMEYAMA Kazuya, NISHI Wataru, NOGAMI Masanori, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2010, 85, "10, 29", 16 Mar. 2010
The Japan Society of Mechanical Engineers, Japanese

S0507-2-3 Experimental Investigation on Bubble Deformation in a Contraction Tube Flow
NISHI Wataru, NOGAMI Masanori, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The proceedings of the JSME annual meeting, 2010, 249, 250, 2010
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., The Japan Society of Mechanical Engineers, Japanese

S0507-2-1 Numerical Simulations of Interactions of Shock Waves with In-line Bubbles
MORIMOTO Mitsuhiro, JINBO Yoshinori, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The proceedings of the JSME annual meeting, 2010, 245, 246, 2010
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., The Japan Society of Mechanical Engineers, Japanese

Numerical Simulations of Two-Phase Flow in Microfluidic Network
NIKI Kazuhiro, KOBAYASHI Kazumichi, 日本流体力学会年会講演論文集, 2010, 97, 97, 2010
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, Japanese

Weakly Nonlinear Analysis for Resonant Gas Oscillations with Evaporation and Condensation
Inaba Masashi, Yano Takeru, Watanabe Masao, Kobayashi Kazumichi, Fujikawa Shigeo, 日本流体力学会年会講演論文集, 2010, 102, 102, 2010
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<

Novel Method for Measurement of Evaporation Coefficient
Nakamura Shigeto, Yano Takeru, Kobayashi Kazumichi, Watanabe Masao, Fujikawa Shigeo, 日本流体力学会年会講演論文集, 2010, 283, 283, 2010
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, Japanese

2006 Collapse of In-Line Bubbles near a Tissue Surface : Effects of Bubble-Bubble Interaction on a Tissue Surface
JINBO Yoshinori, SYU Sei, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The Computational Mechanics Conference, 2009, 22, 554, 555, 10 Oct. 2009
The Japan Society of Mechanical Engineers, Japanese

2005 Numerical Simulations of Bubble Collapse near a Tissue Surface Using the Multi-Grid Ghost Fluid Method : Interface Capturing with Two Level Set Functions
KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The Computational Mechanics Conference, 2009, 22, 552, 553, 10 Oct. 2009
The Japan Society of Mechanical Engineers, Japanese

1004 Experimental Investigation on Bubble Collapse and Propagation of Pressure Wave for Gas-Liquid Two-Phase Flow in Venturi Tube
NOGAMI Masanori, UMEYAMA Kazuya, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2009, 84, "10, 4", 16 Mar. 2009
The Japan Society of Mechanical Engineers, Japanese

1003 Numerical Simulations for Bubble Deformation in Convergent Tube Using Ghost Fluid Method
SHIBAHARA Daikichi, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2009, 84, "10, 3", 16 Mar. 2009
The Japan Society of Mechanical Engineers, Japanese

1012 Molecular Dynamicis Study for Evaporation and Condensation Processes of Thin Liquid Film on Solid Wall
YAMAGUCHI Yoshiaki, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2009, 84, "10, 12", 16 Mar. 2009
The Japan Society of Mechanical Engineers, Japanese

1006 Growth of Microbubbles Covered with Surfactant
IRIE Maya, SAYO Akihito, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2009, 84, "10, 6", 16 Mar. 2009
The Japan Society of Mechanical Engineers, Japanese

28aTK-11 Molecular dynamics simulations for evaporation and condensation phenomena at thin liquid film on solid wall
Kobayashi Kazumichi, Yamaguchi Yoshiaki, Takahira Hiroyuki, Meeting abstracts of the Physical Society of Japan, 64, 1, 289, 289, 03 Mar. 2009
The Physical Society of Japan (JPS), Japanese

Kinetic boundary condition at a vapor-liquid interface of thin liquid layer using the molecular dynamics method
KOBAYASHI Kazumichi, YAMAGUCHI Yoshiaki, TAKAHIRA Hiroyuki, 日本流体力学会年会講演論文集, 2009, 218, 218, 2009
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, Japanese

J0201-1-4 Influence of Gas Diffusion on Growth and Shrinkage of a Microbubble with Surfactant Layers
SAYOU Akihito, IRIE Maya, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The proceedings of the JSME annual meeting, 2009, 103, 104, 2009
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., The Japan Society of Mechanical Engineers, Japanese

754 Bubble Collapse in the Vicinity of a Tissue Surface : Numerical Simulation with the Ghost Fluid Method
SYU Sei, MATSUNO Takahiro, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The Computational Mechanics Conference, 2008, 21, 871, 872, 01 Nov. 2008
The Japan Society of Mechanical Engineers, Japanese

(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, 05 May 2008
一般社団法人日本機械学会, Japanese

509 Numerical Investigations of Bubble Collapse near a Gelatin Surface Using the Ghost Fluid Method
SYU Sei, MATSUNO Takahiro, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2008, 83, "5, 11", 14 Mar. 2008
The Japan Society of Mechanical Engineers, Japanese

508 Axi-symmetric Numerical Simulations of Shock/Bubble Interactions near Mercury-Glass Boundaries
MATSUNO Takahiro, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2008, 83, "5, 10", 14 Mar. 2008
The Japan Society of Mechanical Engineers, Japanese

403 Experimental Investigation on the Mechanism of Bubble Fission in Gas-Liquid Two-Phase Flow Using Venturi Tube
UMEYAMA Kazuya, IKEMA Kengo, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2008, 83, "4, 3", 14 Mar. 2008
The Japan Society of Mechanical Engineers, Japanese

518 Numerical Simulations for Bubble Collapses with Phase Change Based on Molecular Gas Dynamics
KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, 関西支部講演会講演論文集, 2008, 83, "5, 25", 14 Mar. 2008
The Japan Society of Mechanical Engineers, Japanese

1616 Numerical Investigations of Bubble Collapse near a Tissue Surface Using the Ghost Fluid Method
SYU Sei, MATSUNO Takahiro, KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, The proceedings of the JSME annual meeting, 2008, 29, 30, 2008
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., The Japan Society of Mechanical Engineers, Japanese

1115 Numerical Simulations of Single Bubble Dynamics Accompanied with Phase Change Based on Molecular Gas Dynamics(2)
KOBAYASHI Kazumichi, TAKAHIRA Hiroyuki, Fluids engineering conference ..., 2007, "1115, 1"-"1115-4", 17 Nov. 2007
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., The Japan Society of Mechanical Engineers, Japanese

206 A Method of Evaporation-Coefficient Measurement for Liquid by Weak Sound Wave
NAKAMURA Shigeto, KOBAYASHI Kazumichi, INABA Masashi, YANO Takeru, FUJIKAWA Shigeo, 関西支部講演会講演論文集, 2007, 82, "2, 6", 16 Mar. 2007
The Japan Society of Mechanical Engineers, Japanese

On Receiving the Best Presentation Award
KOBAYASHI K., 熱物性 : Japan journal of thermophysical properties, 21, 1, 55, 55, 28 Feb. 2007
Japanese

303 Establishment of Kinetic Boundary Conditions of Methanol and Water on the Basis of Molecular Gas Dynamics Analysis and Shock Tube Experiment(2)
KOBAYASHI Kazumichi, WATANABE Shunsuke, INABA Masashi, YANO Takeru, FUJIKAWA Shigeo, ICHIJO Makoto, Fluids engineering conference ..., 2006, "303, 1"-"303-4", 28 Oct. 2006
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., The Japan Society of Mechanical Engineers, Japanese

303 Establishment of Kinetic Boundary Conditions of Methanol and Water on the Basis of Molecular Gas Dynamics Analysis and Shock Tube Experiment(1)
KOBAYASHI Kazumichi, WATANABE Shunsuke, INABA Masashi, YANO Takeru, FUJIKAWA Shigeo, ICHIJO Makoto, Fluids engineering conference ..., 2006, "303, a", 28 Oct. 2006
The Japan Society of Mechanical Engineers, Japanese

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, +, Sep. 2005
English, Others

925 Determination of Condensation Coefficient for Methanol : Numerical Analysis Based on Molecular Gas Dynamics for Shock Tube Experiment
KOBAYASHI Kazumichi, MIKAMI Satoru, OTA Tatsuki, YANO Takeru, FUJIKAWA Shigeo, ICHIJO Makoto, The proceedings of the JSME annual meeting, 2005, 87, 88, 2005
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., The Japan Society of Mechanical Engineers, Japanese

924 Determination of Condensation Coefficient for Methanol : Measurement of Liquid film Growth By using Optical Interferometer at the Shock Tube Endwall
MIKAMI Satoru, OTA Tatsuki, KOBAYASHI Kazumichi, FUJIKAWA Sigeo, YANO Takeru, ICHIJO Makoto, The proceedings of the JSME annual meeting, 2005, 85, 86, 2005
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., The Japan Society of Mechanical Engineers, Japanese

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, [Peer-reviewed]
English

28pWD-12 Numerical analysis of a film condensation phenomenon of a polyatomic vapor based on molecular gas dynamics
Kobayashi K., Yano T., Fujikawa S., Meeting abstracts of the Physical Society of Japan, 59, 1, 299, 299, 03 Mar. 2004
The Physical Society of Japan (JPS), Japanese

Numerical Analysis of Plane Shock Wave in Polyatomic Molecule Gas Based on Molecular Gas Dynamics
KOBAYASHI Kazumichi, YANO Takeru, FUJIKAWA Shigeo, The proceedings of the JSME annual meeting, 2004, 373, 374, 2004
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., The Japan Society of Mechanical Engineers, Japanese

Numerical Simulations of Condensation Phenomena of a Polyatomic Vapor behind a Reflected Shock Wave
KOBAYASHI Kazumichi, YANO Takeru, FUJIKAWA Shigeo, 北海道支部講演会講演概要集, 2003, 43, 196, 197, 28 Sep. 2003
The Japan Society of Mechanical Engineers, Japanese

Numerical Analysis of Condensation Phenomenon of Methanol Vapor in a Shock Tube
KOBAYASHI Kazumichi, YANO Takeru, FUJIKAWA Shigeo, Fluids engineering conference ..., 2003, 94, 94, 18 Sep. 2003
The Japan Society of Mechanical Engineers, Japanese

Molecular Gas Dynamics Simulation of Phase Change of Polyatomic Molecule Vapor in Nonequilibrium State
KOBAYASHI Kazumichi, YANO Takeru, FUJIKAWA Shigeo, 北海道支部講演会講演概要集, 2002, 42, 114, 115, 05 Oct. 2002
The Japan Society of Mechanical Engineers, Japanese

Books and other publications

Influence of condensation coefficient on spherical bubble collapse with evaporation and condensation　　　　　　　　　　　　　　　
S. Morikawa, Y. Tatekura, K. Kobayashi, H. Fujii, M. Watanabe, K. Sasaki
Japanese Society of Fluid Mechanics，NAGARE, May 2017, 105-108, Japanese, Scholarly book, ながれ NAGARE 36, [Joint work]

Liquid temperature dependence of kinetic boundary condition at vapor–liquid interface　　　　　　　　　　　　　　　
Misaki Kon, Kazumichi Kobayashi, Masao Watanabe
Advanced in Engineering, Mar. 2017, English, Report, https://advanceseng.com/mechanical-engineering/liquid-temperature-dependence-kinetic-boundary-condition-vapor-liquid-interface/, [Joint work]

Laboratory of Fluid Dynamics, Division of Mechanical and Space Engineering, Hokkaido University　　　　　　　　　　　　　　　
Masao Watanabe, Kazumichi Kobayashi, Hiroyuki Fujii
Japanese Journal of Multiphase Flow, Dec. 2016, [Joint work]

Mass, Momentum, and Energy transfer at vapor-liquid interface Chapter 5 Shock Tube Experiment of Evaporation and Condensation　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Shigeo Fujikawa
Japanese Society of Fluid Mechanics，NAGARE, Dec. 2014, 543-548, Japanese, Scholarly book, ながれ Nagare 33, [Joint work]

Report of JSMF Symposium on Multiphase Flow 2014　　　　　　　　　　　　　　　
Yuichi Murai, Kazumichi Kobayashi
混相流 Vol.28 No.4 日本混相流学会, Dec. 2014, 4, Japanese

Mass, Momentum, and Energy transfer at vapor-liquid interface Chapter 4 Application of Molecular Gas Dynamics to Evaporation and Condensation　　　　　　　　　　　　　　　
Kazumichi Kobayashi, Shigeo Fujikawa
Japanese Society of Fluid Mechanics，NAGARE, Oct. 2014, 453-459, ながれ NAGARE 33, [Joint work]

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, Oct. 2013, 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

Nonlinear Resonant Gas Oscillation with Evaporation and Condensation　　　　　　　　　　　　　　　
Masashi Inaba, Takeru Yano, Kazumichi Kobayashi, Masao Watanabe
Japanese Society of Fluid Mechanics，NAGARE, Dec. 2012, 487-490, Japanese, Scholarly book, ながれ NAGARE 31, [Joint work]

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, 14-19, [Joint work]

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, Japanese, http://www.jsme-fed.org/newsletters/2009_9/no5.html#ctop

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

Lectures, oral presentations, etc.

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, 11 Jul. 2023, English, Oral presentation
09 Jul. 2023 - 13 Jul. 2023, 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, 05 Jul. 2022, English, Oral presentation
04 Jul. 2022 - 08 Jul. 2022, 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, 07 Jul. 2021, English, Oral presentation
07 Jul. 2021 - 09 Jul. 2021, 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, 27 Nov. 2019, English, Invited oral presentation
[Invited], [International presentation]

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, 23 Nov. 2019, English, Oral presentation
[International presentation]

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), 06 Jun. 2019, English, Poster presentation
[International presentation]

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), Jul. 2018, English, Oral presentation
[International presentation]

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), May 2018, English, Poster presentation
SWEP BOOK of Abstract, p. 27, [International presentation]

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, Nov. 2017, English, Oral presentation
1 page, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1526, 4 pages, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1491, 5 pages, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1334, 4 pages, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1485, 4 pages, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1173, 3 pages, [International presentation]

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, Oct. 2017, English, Oral presentation
TFEC9-1492, 4 pages, [International presentation]

Molecular Gas Dynamics Analysis of the Collapse of Microbubble Accompanied with Heat and Mass Transfer at Gas-Liquid Interface　　　　　　　　　　　　　　　
Kazumichi Kobayashi
JSME Annual meeting, 04 Sep. 2017, Japanese, Invited oral presentation
【招待講演】, [Invited], [Domestic Conference]

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　　　　　　　　　　　　　　　
Kazumichi Kobayashi
Annual meeting of JSMF, 21 Aug. 2017, Japanese, Invited oral presentation
【招待講演】, [Invited], [Domestic Conference]

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, 22 Jun. 2017, English, Invited oral presentation
【招待講演】, [Invited], [International presentation]

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, Jun. 2017, English, Oral presentation
B62, 2 pages, [International presentation]

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, Nov. 2016, English, Oral presentation
[International presentation]

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, Oct. 2016, English, Oral presentation
[International presentation]

Nanoscale Thermal Fluid Dynamic at Vapor-Liquid Interface　　　　　　　　　　　　　　　
Kazumichi Kobayashi
JSME Annual meeting, 12 Sep. 2016, JSME, Japanese, Invited oral presentation
九州大学伊都キャンパス, 【招待講演】, [Invited], [Domestic Conference]

Molecular simulation of evaporation mass flux during net evaporation/condensation
Misaki Kon, Kobayashi Kobayashi, Masao Watanabe
The 30th International Symposium on Rarefied Gas Dynamics, 10 Jul. 2016, English, Oral presentation
University of Victoria Victoria BC Canada, AIP Conf. Proc., Vol. 1786, 110001 (2016), [International presentation]

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, 10 Jul. 2016, English, Oral presentation
University of Victoria Victoria BC Canada, AIP Conf. Proc., 1786, 110002, (2016), [International presentation]

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), May 2016, English, Oral presentation
[International presentation]

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), May 2016, English, Oral presentation
[International presentation]

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), May 2016, English, Oral presentation
[International presentation]

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), May 2016, English, Oral presentation
[International presentation]

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, AMER INST PHYSICS, English
2016 - 2016, 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, 08 Dec. 2015, English, Oral presentation
Eindhoven, the Netherlands, Proceedings of 2nd European conference on non-equilibrium gas flow, No. 50, 1 page., [International presentation]

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, 03 Dec. 2015, IOP Publishing, English
03 Dec. 2015 - 03 Dec. 2015, 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), Dec. 2015, English, Oral presentation
[International presentation]

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), Dec. 2015, English, Oral presentation
[International presentation]

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, Oct. 2015, English, Oral presentation
[International presentation]

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, May 2015, English
【Invited】Total 1 page, [Invited], [International presentation]

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, SPIE-INT SOC OPTICAL ENGINEERING, English
2015 - 2015, 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, 13 Jul. 2014, English, Oral presentation
Xi'an, China, AIP Conf. Proc. 1628, 404 (2014); http://dx.doi.org/10.1063/1.4902621, [International presentation]

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, 13 Jul. 2014, English, Oral presentation
Xi'an, China, AIP Conf. Proc. 1628, 398 (2014); http://dx.doi.org/10.1063/1.4902620, [International presentation]

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, 23 May 2013, English
No. 260, Total 5 pages, [International presentation]

Numerical simulations of impact pressure generated by single-droplet impact　　　　　　　　　　　　　　　
Yuki Tatekura, Kazumichi Kobayashi, Masao Watanabe
8th International Conference on Multiphase Flow, 23 May 2013, English, Oral presentation
No. 521, Total 5 pages, [International presentation]

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, English
No. 41, Total 6 pages, 2013, [International presentation]

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, Jul. 2012, English, Oral presentation
AIP Conf. Proc., [International presentation]

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, Jul. 2012, English, Invited oral presentation
【INVITED】AIP Conf. Proc., [Invited], [International presentation]

Resonant Gas Oscillation with Evaporation and Condensation　　　　　　　　　　　　　　　
M. Inaba, T. Yano, M. Watanabe, K. Kobayashi
19th International Symposium on Nonlinear Acoustics, 2012, English, Oral presentation
AIP Conf. Proc., No. 1474, pp.79-82, (2012)., [International presentation]

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, English, Oral presentation
AIP Conf. Proc.,No. 1474,
pp.143-146, (2012)., [International presentation]

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, English, Oral presentation
Total 6 pages (CD-ROM), (2012), [International presentation]

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, English, Oral presentation
Total 6 pages (CD-ROM), [International presentation]

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, English, Oral presentation
Total 2 pages (CD-ROM), (2012)., [International presentation]

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, 04 Oct. 2011, The Electrochemical Society, English
04 Oct. 2011 - 04 Oct. 2011, 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, English
Paper No. AJK2011-33019, pp. 251-256 (2011)., [International presentation]

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, English, Oral presentation
Paper No. AJK2011-33017, pp. 237-241 (2011)., [International presentation]

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, English, Oral presentation
ECS Transaction, Vol.41, pp. 67-74 (2011)., [International presentation]

Numerical Analysis of Shock-Bubble Interactions near Tissue Boundaries　　　　　　　　　　　　　　　
Kazumichi Kobayashi
6th Japan-Taiwan Workshop on Mechanical and Aerospace Engineering, 2011, English, Oral presentation
Total 8 pages(CD-ROM), (2011)., [International presentation]

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, English, Oral presentation
Journal of Acoustic Society of America, 124, 2712, [International presentation]

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, English, Oral presentation
Total 11 pages (CD-ROM), No.53, (2009), [International presentation]

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, English, Oral presentation
Total 2 pages (CD-ROM，No.E322), (2008), [International presentation]

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, English, Oral presentation
Total 2 pages (CD-ROM, No.E313), (2008)., [International presentation]

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, English, Oral presentation
Total 2 pages (CD-ROM，No.E122), (2008)., [International presentation]

Molecular Gas Dynamics Simulation of the Collapse of Condensable Gas bubbles　　　　　　　　　　　　　　　
K. Kobayashi, H. Takahira
Cavitation in Turbo-Machinery & Medical Applications, 2008, English, Oral presentation
pp.204-209(CD-ROM), (2008), [International presentation]

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, English, Oral presentation
pp.190-194, (CD-ROM), (2008)., [International presentation]

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, English, Oral presentation
Total 10 pages (CD-ROM), (2007)., [International presentation]

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, English, Oral presentation
Total 5 pages (CD-ROM, No.A10-4),(2006), [International presentation]

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, English, Oral presentation
Total 4 pages (CD-ROM, No.70), (2005), [International presentation]

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, English, Oral presentation
Total 5 pages (CD-ROM, No.7-b-7), (2005)., [International presentation]

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, English, Oral presentation
Total 9 pages (CD-ROM, No.413), (2004)., [International presentation]

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, English, Oral presentation
Total 5 pages (CD-ROM, No.101), (2004)., [International presentation]

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, English, Oral presentation
Total 6 pages (CD-ROM, No. FEDSM2003-45022), (2003)., [International presentation]

Courses

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

Affiliated academic society

Apr. 2024 - Present
The Heat Transfer Society of Japan

THE JAPANESE SOCIETY FOR MULTIPHASE FLOW

The Japan society of Thermophsical Properties

THE JAPAN SOCIETY OF FLUID MECHANICS

THE PHYSICAL SOCIETY OF JAPAN

THE JAPAN SOCIETY OF MECHANICAL ENGINEERS

Research Themes

準液滴の科学：水の転成が生む混沌と秩序
科学研究費助成事業
Apr. 2025 - Mar. 2030
佐藤岳彦, 由井宏治, 谷垣実, 原田慈久, 藤村茂, 伊賀由佳, 小林一道, 立花孝介, 劉思維, 宮原高志
日本学術振興会, 基盤研究(S), 東北大学, 25H00405

Evaporation coefficient of nanoparticle suspension
Grants-in-Aid for Scientific Research
01 Apr. 2024 - 31 Mar. 2028
小林一道, 藤井宏之, 渡部正夫
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 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
Apr. 2024 - Mar. 2026
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

Relaxation of intramolecular vibration of solvents by infrared excitation and clarification of effective infrared absorption wavelength band for solvent drying
Grants-in-Aid for Scientific Research
01 Apr. 2022 - 31 Mar. 2025
戸谷剛, 小林一道
2023年度は、下記の2項目を行った。(2023-1)溶剤(水)の蒸発に最も効果的な分子内振動(赤外線吸収波長帯)の解明実験、(2023-2)緩和挙動を組み込んだ平均場分子運動論解析・分子動力学解析法の開発と溶剤の蒸発量を計算する計算手法の確立
(2023-1)では、計画通り、波長制御エミッタから放射されたふく射をポンプ光として、プローブ光と同じ溶剤の下方から当て、溶剤の分子内振動を励起する実験系を構築した。この実験系でも、反射スペクトルを取得する溶剤表面を、熱伝導で加熱するよりも、波長制御エミッタで加熱した方が、溶剤の表面温度は同じにも関わらず、蒸発につながる分子間振動が促進される緩和挙動が確認された。しかし、昨年度確認された反射スペクトルの差より小さく、観測しにくかったため、今年度は、実験系を昨年度の系に戻して、実験を行うことにした。波長3.03 μmに単色放射能のピークを持つ波長制御エミッタと波長6.10 μmに単色放射能のピークを持つ波長制御エミッタを用いた加熱実験を、単色放射能のピークが同じになるようにそれぞれ行った結果、蒸発につながる分子間振動の励起には有意な差が出ないことが確認された。
(2023-2)では、昨年度に引き続き平均場分子運動論を用いて温度の異なる二液膜問題について研究を行った。その結果、過去の分子動力学解析結果と同様の傾向で蒸発界面の速度分布関数が非等方性を持つことを確認した。この結果より、本解析の平均場分子運動論への有用性を確認することができた。また、凝縮界面についても，蒸発界面とは異なる傾向で速度分布関数が非等方性を持つことがわかった。さらに、本計算を大規模分子動力学解析で行うための予備調査も行った。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K22678

Relaxation of intramolecular vibrations of solvents by infrared excitation and elucidation of effective infrared absorption wavelength band for drying solvent
Grants-in-Aid for Scientific Research
Apr. 2022 - Mar. 2025
戸谷剛, 小林一道
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Coinvestigator, 22H01407

Molecular Fluid Dynamics of AWAI
Presto
Oct. 2021 - Mar. 2025
Kazumichi Kobayashi
Japan Science and Technology Agency, Hokkaido University, Principal investigator, 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)
01 Apr. 2020 - 31 Mar. 2023
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

Influence of the interference effects on radiative transfer in dense colloidal suspensions
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2020 - 31 Mar. 2023
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。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 20H02076

Elucidation of non-equilibrium phase change at gas-liquid interface mechanism for mixture gas and its application to molecular multi-phase fluid dynamics
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Apr. 2020 - Mar. 2023
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．
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 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
Apr. 2019 - Mar. 2022
戸谷剛, 小林一道
日本学術振興会, Competitive research funding

Gas molecular behaviors in pore　　　　　　　　　　　　　　　
Joint Research
Jul. 2020
corporation, Hokkaido University, Principal investigator, Industry academia cooperation

Gas molecular behaviors in pore　　　　　　　　　　　　　　　
Joint Research
Dec. 2019 - Jun. 2020
corporation, Hokkaido University, Principal investigator, Industry academia cooperation

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
Apr. 2018 - Mar. 2020
Masao Watanabe
日本学術振興会, Competitive research funding

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
Apr. 2017 - Mar. 2020
渡部正夫
日本学術振興会, Competitive research funding

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
Apr. 2019 - Dec. 2019
小林一道
公益信託小野音響学研究助成基金, Principal investigator, Competitive research funding

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
Apr. 2016 - Mar. 2019
小林一道
日本学術振興会, Principal investigator, Competitive research funding

Condensation effect on high-speed liquid-film flow instability at a liquid-droplet impact on a solid surface in a vaporous environment
Grants-in-Aid for Scientific Research
01 Apr. 2014 - 31 Mar. 2017
WATANABE MASAO
Droplet impacts on solid surface are key elements in technical applications, such as rapid spray cooling, ink-jet printing and semiconductor cleaning. Although the broad varieties of parameters that control splash formation after the droplet impact, are proposed, they are not thoroughly explored; hence, dynamics of the droplet after the impact are yet fully understood. After droplet impacts on solid surface, characteristic film flow is developed; then splash may be generated. In this study, we examine the effects of the temperature of surrounding gas, which is either condensable or non-condensable, on ethanol droplet impact. We found that splash can be suppressed with the increase of the surrounding gas temperature. We measured the splash threshold pressure for a splash to appear as a function of the temperature. The results show that the splash threshold pressure is a monotonically increasing function of the surrounding gas temperature.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 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
Apr. 2014 - Mar. 2016
渡部正夫
日本学術振興会, Competitive research funding

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
Grant-in-Aid for Scientific Research (KAKENHI)
Apr. 2013 - Mar. 2016
小林一道
Japan Society for the Promotion of Science, Principal investigator, Competitive research funding

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
Apr. 2015 - Feb. 2016
小林一道
ノーステック財団研究開発助成事業, Principal investigator, Competitive research funding

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
Apr. 2013 - Mar. 2014
小林一道
北海道ガス, Principal investigator, Competitive research funding

Study on Transport phenomena at supercritical mixure interface by moelcular velocity distribution function and mean field kinetic theory
Grants-in-Aid for Scientific Research
Apr. 2011 - Mar. 2013
Masao Watanabe
Transport phenomena on vapor-liquid mixture interface is studied for the accurate prediction of fuel mixture concentration,which leads to the development of highly reliable liquid fuel rocket engine. Numerical simulations f()r vapor liquid twophase systems were perf()mled by using the mean field kinetic theory.The kinetic boundaiy condition(KBC)at theinterface was investigated. We also execute molecular dynamics simulations oftwo-component vapor-liquid equilibrium systemsofbinary system to investigate heat/mass transport phenomena on mixtUre interface.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, Competitive research funding, 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
Grant-in-Aid for Scientific Research (KAKENHI)
Apr. 2010 - Mar. 2013
Kazumichi Kobayashi
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．
Japan Society for the Promotion of Science, Principal investigator, Competitive research funding

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
Apr. 2010 - Mar. 2013
渡部正夫
日本学術振興会, Competitive research funding

気泡崩壊現象における極限物理の解明
Grant-in-Aid for Scientific Research (KAKENHI)
Apr. 2009 - Mar. 2013
高比良裕之
Japan Society for the Promotion of Science, Competitive research funding

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
Japan Society for the Promotion of Science
Apr. 2009 - Mar. 2011
藤川重雄
Japan Society for the Promotion of Science, Competitive research funding

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
Grant-in-Aid for Scientific Research (KAKENHI)
Apr. 2009 - Mar. 2011
渡部正夫
Japan Society for the Promotion of Science, Competitive research funding

Determination of evaporation and condensation coefficients and new approach for bubble dynamics using molecular dynamics and molecular gas dynamics
Grant-in-Aid for Scientific Research (KAKENHI)
Apr. 2007 - Mar. 2009
Kazumichi Kobayashi
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．
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (Start-up), Osaka Prefecture University, Principal investigator, Competitive research funding, 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
Apr. 2006 - Mar. 2007
小林一道
日本学術振興会, Principal investigator, Competitive research funding

Evaporation/Condensation Phenomena, Numerical Simulation of Kinetic Theory of Gases, Molecular Dynamics　　　　　　　　　　　　　　　
Competitive research funding

syllabus

流体工学特論, 2024年, 修士課程, 工学院

分子流体力学特論, 2024年, 修士課程, 工学院

分子流体力学特論, 2024年, 修士課程, 工学院

流体工学特論, 2024年, 博士後期課程, 工学院

分子流体力学特論, 2024年, 博士後期課程, 工学院

分子流体力学特論, 2024年, 博士後期課程, 工学院

熱流体力学演習Ⅰ, 2024年, 学士課程, 工学部

流体工学, 2024年, 学士課程, 工学部

Kobayashi Kazumichi

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