Terashima Hiroshi

Faculty of Engineering　Mechanical and Aerospace Engineering　Aerospace SystemsAssociate Professor
Last Updated :2025/12/04

■Researcher basic information

Degree

  • Ph.D.

Researchmap personal page

Home Page URL

Researcher number

  • 20415235

J-Global ID

Research Keyword

  • 数値流体力学
  • 燃焼反応流体
  • 超臨界流体
  • 気液界面
  • 空力弾性

Research Field

  • Informatics, Computational science
  • Aerospace, marine, and maritime Engineering, Aerospace engineering
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Thermal engineering
  • Social infrastructure (civil Engineering, architecture, disaster prevention), Safety engineering
  • Social infrastructure (civil Engineering, architecture, disaster prevention), Social systems engineering

Educational Organization

■Career

Career

  • Oct. 2025 - Present
    JAXA, 研究開発本部第三研究ユニット, 主幹研究開発員（クロスアポイントメント）
  • Dec. 2015 - Present
    Hokkaido University, Faculty of Engineering, Associate Professor
  • Apr. 2023 - Mar. 2024
    Stanford University, Department of Mechanical Engineering, Visiting associate professor
  • Apr. 2013 - Nov. 2015
    University of Tokyo, School of Engineering, Project Associate Professor
  • Apr. 2011 - Mar. 2013
    The University of Tokyo, 工学系研究科, 特任助教
  • Apr. 2009 - Mar. 2011
    JAXA, JEDI, Aerospace Project Researcher
  • Apr. 2007 - Mar. 2009
    Worcester Polytechnic Institute, Mechanical Engineering Department, Research Scientist
  • Apr. 2005 - Mar. 2007
    理化学研究所, 研究員（2006年11月より客員研究員）
  • Apr. 2004 - Mar. 2005
    The University of Tokyo, IML, 機関研究員

Educational Background

  • Apr. 2000 - Mar. 2004, The University of Tokyo, 航空宇宙工学専攻 博士課程
  • Apr. 1998 - Mar. 2000, Tohoku University, 航空宇宙工学専攻 博士課程前期
  • Apr. 1994 - Mar. 1998, Tohoku University, Faculty of Engineering, 機械航空工学科

■Research activity information

Awards

  • 2016, 日本燃焼学会, 平成28年度日本燃焼学会 奨励賞　　　　　　　　　　　　　　　
    寺島洋史

Papers

Other Activities and Achievements

Books and other publications

  • High-pressure flows for propulsion applications
    Bellan, Josette, American Institute of Aeronautics and Astronautics, Detailed Modeling of Supercritical Jets and Flames, pp. 571–630
    American Institute of Aeronautics and Astronautics, 2020, 9781624105807, xiv, 787 p., English
  • 1) 計算力学ハンドブック「第II巻 差分法・有限体積法（熱流体編）」　　　　　　　　　　　　　　　
    寺島洋史, 第4章圧縮性流れ第5項連成問題
    日本機械学会，丸善, 2006, [Contributor]

Lectures, oral presentations, etc.

  • A computational study for combustion flow fields of a high-pressure gaseous hydrogen/oxygen coflow jet behind a splitter plate
    Shun Murakami, Hiroshi Terashima, Nobuyuki Oshima
    AIAA Scitech 2019 Forum, 01 Jan. 2019
    © 2019 by Timothy K. Minton. Published by the American Institute of Aeronautics and Astronautics, Inc. A computational study is performed for exploring flow and flame dynamics of a high-pressure hydrogen/oxygen coflow jet with the effects of post thickness and moment flux ratio. A two-dimensional model with a splitter plate, which represents a post configuration of an injector of rocket engines, is adapted to fully resolve the combustion flow field. The compressible Navier-Stokes equations are solved with a detailed chemical kinetic mechanism in a manner of direct numerical simulation. The result shows that the post thickness largely affects the temperature distribution in a recirculation region established behind the post. The temperature distribution is determined with the amount of incoming high-temperature combustion gas and unburned hydrogen gas, which significantly changes with the post thickness. The effect of the momentum flux ratio clearly appears in the case of thicker post configuration, while in the case of thinner post configuration no major differences are identified for all the momentum flux ratio. The study shows a tendency that thicker post geometries with smaller J numbers provide lower temperature fields in the recirculation region behind the post, thus preliminarily indicating some difficulty of maintaining a flame anchoring in the recirculation region.
  • 定容容器におけるエンドガス局所自着火現象の可視化
    藤田晴彦, 伊藤祐太朗, 山田眞平, 下栗大右, 佐藤伴音, 寺島洋史, 河野通治, 本田雄哉, 植木義治, 横畑英明
    日本伝熱シンポジウム講演論文集(CD-ROM), 2017, Japanese
  • 柔軟構造体に対する再突入ブラックアウトの数値解析
    榎尚也, 松永学, 高橋裕介, 寺島洋史, 大島伸行
    流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM), 2017, Japanese
  • 観測ロケットを用いた柔軟構造体の再突入試験における空力不安定性解析
    大橋達志, 松永学, 高橋裕介, 寺島洋史, 大島伸行
    流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM), 2017, Japanese
  • Numerical simulation for effects of pressure on cryogenic coaxial jet under supercritical pressure
    Takahide Araki, Daiki Muto, Hiroshi Terashima, Nobuyuki Tsuboi
    AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting, 01 Jan. 2017
    © 2017 by Rolls-Royce North America Holdings Inc. Three-dimensional numerical simulations of coaxial nitrogen jet mixing under supercritical pressures are performed with an emphasis on the effects of pressure on the mixing. The results show that the overall mixing behaviors are similar in terms of normalized density profiles between 5 and 12 MPa. However, the normalized temperature profiles are different between two conditions because non-linear change of the density to the temperature near the critical point. The peak of the constant pressure specific heat is particularly observed in the case of 5 MPa. The density and temperature fluctuations become large between the inner jet flow and the outer jet flow. Although the density fluctuation distributions are similar between two cases, the larger fluctuation region of temperature is observed in the case of 5 MPa. This is because the temperature increases are different near the critical temperature between two pressure conditions.
  • ノッキング現象におけるホットスポットの源について
    寺島洋史, 松木亮
    燃焼シンポジウム講演論文集, 26 Nov. 2016, Japanese
  • 着火遅れ時間特性と末端ガス自着火・圧力波強度の関係:容器圧力条件を変化させたノッキング解析
    佐藤伴音, 寺島洋史, 大島伸行
    燃焼シンポジウム講演論文集, 26 Nov. 2016, Japanese
  • 高圧メタン酸素ロケット噴射器近傍の非定常燃焼流れ場構造:詳細反応機構を用いたCFD解析
    寺島洋史, 大門優
    日本機械学会熱工学コンファレンス講演論文集(CD-ROM), 2016, Japanese
  • 超臨界圧力下における極低温同軸噴流への噴射条件の影響
    武藤大貴, 武藤大貴, 寺島洋史, 坪井伸幸
    数値流体力学シンポジウム講演論文集(CD-ROM), 2016, Japanese
  • Interface-tracking simulationsof droplet vaporization and burning of hypergolic propellants
    Hiroumi Tani, Yutaka Umemura, Yu Daimon, Hiroshi Terashima, Mitsuo Koshi
    54th AIAA Aerospace Sciences Meeting, 01 Jan. 2016
    © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA, All rights reserved. The vaporization and burning of the N 2 H 4 and NTO droplets were simulated with the interface-tracking method to accurately explore the auto-ignition processes and the flame structures. The N 2 H 4 vapor plume developed behind the N 2 H 4 droplet and reacted with the ambient NO 2 gas through the hydrogen abstraction reactions. Thus, the N 2 H 4 vapor and NO 2 gas mixtures behind the droplet were preheated and reached the auto-ignition at a few ms. The auto-ignition occurred in the multiple points almost at the same time. After the ignition, the premixed flame developed around the droplet. Thus, the vaporization of the liquid N 2 H 4 near the surface became significant. Then, the double flame structures which comprise the inner decomposition flame and oxidation flame appeared around the droplet. The NTO droplet was not auto-ignited in the computational time of the present study because little N 2 O4 vapor near a saturated temperature decomposed to NO 2 gas which is necessary for the hydrogen abstraction reactions. When the ignition was forced, the double flames developed. The outer decomposition flame propagated to the boundaries of the computational domain, while the inner oxidation flame appeared near the droplet. Except for the propagation of the decomposition flame, the NTO droplet combustion was similar to that of the industrial fuels.
  • Numerical simulation of jet mixing in a recessed coaxial injector at supercritical pressure
    Daiki Muto, Hiroshi Terashima, Nobuyuki Tsuboi
    54th AIAA Aerospace Sciences Meeting, 01 Jan. 2016
    © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Three-dimensional numerical simulations of cryogenic coaxial jets under supercritical pressure are performed with flushed and recessed injectors to investigate the effect of a recess on the coaxial mixing. A hybrid ILES/RANS method is applied to simulate wallbounded injectors and a recessed region. The recessed injector enhances the density decay and the temperature increase on the central axis, indicating the improvement of mixing compared with the flushed injector. However, the mixing improvement by the recess is not significant in the present conditions. The recess also induces distinct vortex rings around the outer jet. The power spectra of the velocity fluctuations also demonstrated that the low-frequency velocity fluctuations are clearly induced by the recess which frequency corresponds to the large vortex structures.
  • Three-dimensional structures in hypergolic ignition process and flame holding mechanisms for hydrazine/nitrogen dioxide un-like doublet impinging gas jets
    Yu Daimon, Hiroumi Tani, Hiroshi Terashima, Mitsuo Koshi
    54th AIAA Aerospace Sciences Meeting, 01 Jan. 2016
    © 2016 by the American Institute of Aeronautics, and Astronautics, Inc. All rights reserved. Hydrazine (N 2 H 4 )/nitrogen dioxide (NO 2 ) un-like doublet impinging gas jets were simulated to explore the hypergolic ignition processes in a N 2 H 4 /N 2 O4 bipropellant thruster. The three-dimensional compressible Navier-Stokes equations with a detailed chemical kinetics mechanism, in which more than 200 chemical reactions were directly taken into account, were solved to reveal the influence of the chemical reaction. The differences of three-dimensional structures of hypergolic ignition process and mechanism of flame holding between the two different inlet gas temperatures of 400 and 600 K were discussed in order to investigate the influence of the induction time of chemical reaction on the three-dimensional flowfield. The computed results clarified that the ignition time of impinging gas jets can be significantly influenced by the ignition delay of the detailed chemical kinetics mechanism. In addition, the intermittent multi-ignitions played a significant role in the mechanism of flame holding.
  • Generations of unstable combustion in a non-premixed GCH4/GOX rocket injector
    H. Terashima, Y. Daimon
    52nd AIAA/SAE/ASEE Joint Propulsion Conference, 2016, 01 Jan. 2016
    © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. A two-dimensional detailed numerical simulation is performed for combustion flow field of a GCH4/GOX single injector using detailed chemical kinetics with the compressible Navier-Stokes equations. A detailed mechanism of CH4, 33 chemical species and 150 re- actions, is efficiently and directly introduced. The result shows that the relatively high- temperature and CH4-rich recirculation region is established in the upper and lower corners of the combustion chamber. The result, with a at inlet profile, interestingly shows the generation of an unstable combustion mode, which is not observed with a smooth inlet pro- file. It is shown that the disappearance of non-premixed flames behind the GOX post is a trigger for the unstable combustion mode through the production of partly premixed gases and the generation of autoignition at several locations in the combustion chamber, which may be caused by the extent of the incursion of GCH4 and GOX jets in the recirculation region behind the GOX post.
  • Effects of injector geometry on co-flowing planar jet mixings under supercritical pressures
    Daiki Muto, Nobuyuki Tsuboi, Hiroshi Terashima
    53rd AIAA Aerospace Sciences Meeting, 01 Jan. 2015
    © 2015 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. The effects of the injector geometries on co-flowing planar cryogenic jet mixings under a supercritical condition are numerically investigated. The present study focuses the recess of the coaxial injector which is widely applied in practical liquid rocket engines. The present numerical method applies an ILES/RANS hybrid method to simulate the jet mixing in the wall-bounded recessed region. As a validation of the present method, a mono-planar jet and a round jet simulations are carried out, and the results agree well with an experimental result. To examine the effects of the recess length on the coaxial injections, two-dimensional co-planar jet simulations at the supercritical pressure are performed in three recess lengths. The recessed cases show the strong flapping motions of the high densty jet, and as a result, the injected fluids are mixed well compared with the case without the recess. While there is a small difference on the potential core length between the cases without the recess and the shorter recess, the longer recess case largely shortens the jet core.
  • Hypergolic ignition and flame structures of hydrazine spray/gaseous nitrogen tetroxide co-flowing jets
    Hiroumi Tani, Hiroshi Terashima, Ryoichi Kurose, Tomoaki Kitano, Mitsuo Koshi, Yu Daimon
    53rd AIAA Aerospace Sciences Meeting, 01 Jan. 2015
    © 2015 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Hydrazine (N 2 H 4 ) spray/gaseous nitrogen tetroxide (NTO) co-flowing jets were simulated to explore the hypergolic combustion flows in N 2 H 4 /NTO bipropellant thrusters. The Navier-Stokes equations with the use of a detailed chemical kinetics mechanism and dispersed droplets with evaporation models were solved in a manner of direct numerical simulations. The influence of the evaporation of N 2 H 4 droplets upon the hypergolic ignition processes and flame structures was investigated. Before the auto-ignition, the N 2 H 4 vapor and the ambient NTO gas mixtures were preheated as a result of the hydrogen abstraction reactions, whereas the evaporation of the N 2 H 4 droplets decreased the temperature of the gas mixtures. When the temperature of the NTO flows was sufficiently high, the N 2 H 4 vapor and NTO gas mixtures were preheated and could auto-ignite near the leading edge of the N 2 H 4 spray. This occurred because the heat transfer from the ambient gases to the droplets and the N 2 H 4 vapor enhanced the hydrogen abstraction reactions in the leading edge. After the auto-ignition, the double flame structure appeared, comprising the outer diffusion flames and inner decomposition flame. Interestingly, the inner decomposition flame and the N 2 H 4 vapor flow exhibited a sinusoidal behavior. This behavior was initiated by the locally expanded decomposition gases and developed by the supply of the N 2 H 4 droplets to the decomposition gases at relatively high temperatures. When the droplet size was small, the auto-ignition was not always enhanced because the temperature of the N 2 H 4 vapor and the NTO gas mixtures decreased. Furthermore, the sinusoidal behavior of the inner decomposition flame was less significant because the flame’s development depended on the temperature of the N 2 H 4 vapor and inertial mass of the droplets.
  • Numerical study on mixing characteristics of coaxial cryogenic N2/H2 injection under supercritical pressure
    Hiroshi Terashima, Mitsuo Koshi
    52nd Aerospace Sciences Meeting, 01 Jan. 2014
    © 2014, American Institute of Aeronautics and Astronautics Inc. All rights reserved. Three-dimensional simulations for nitrogen/hydrogen mixing of a shear coaxial injector under supercritical pressures are conducted in order to investigate their mixing characteristics. A high-order numerical method based on a sixth-order compact scheme is applied. The present study parametrically covers two pressures of 4 and 8 MPa and two outer hydrogen jet conditions, while an inner nitrogen jet condition and a mixture ratio are kept to be same. The discussions on mean and fluctuation properties in addition to instantaneous flow fields are made in order to characterize mixing features for the coaxial injection. A colder outer hydrogen jet provides less mixing behavior compared to a warmer hydrogen jet, generating a longer dense-core of the inner nitrogen jet; unmixed nitrogen and hydrogen remain in downstream regions. Some unique features are found in the temperature profiles on the centerline of inner nitrogen jet as a flattened or a wave-like profile under 4 MPa, while no such unique features are not observed under 8 MPa. In the case of a warmer outer hydrogen jet, the hydrogen density show a maximum peak just after the injection because of the heat transfer to the inner nitrogen jet. The density and temperature fluctuation distributions are determined by the unique thermodynamic fluid variations around the critical temperature, and the velocity and temperature differences among two jets and chamber fluid. Finally, a clear dependence of dense-core length on the momentum flux ratio is demonstrated on comparison with experimental and computational data.
  • Numerical Simulation on Soot Formation in Diesel Combustion by Using a CFD Code Combined with a Parallelized Explicit ODE Solver
    Akira Kikusato, Kazuya Kogo, Beini Zhou, Kusaka Jin, Yasuhiro Daisho, Kiyotaka Sato, Hidefumi Fujimoto, Hiroshi Terashima, Youhi Morii
    SAE Technical Papers, 01 Jan. 2014
    Copyright © 2014 SAE International. The objective of the present study is to analyze soot formation in diesel engine combustion by using multi-dimensional combustion simulations with a parallelized explicit ODE solver. Parallelized CHEMEQ2 was used to perform detailed chemical kinetics in KIVA-4 code. CHEMEQ2 is an explicit stiff ODE solver developed by Mott et al. which is known to be faster than traditional implicit ODE solvers, e.g., DVODE. In the present study, about eight times faster computation was achieved with CHEMEQ2 compared to DVODE when using a single thread. Further, by parallelizing CHEMEQ2 using OpenMP, the simulations could be run not only on calculation servers but also on desktop machines. The computation time decreases with the number of threads used. The parallelized CHEMEQ2 enabled combustion and emission characteristics, including detailed soot formation processes, to be predicted using KIVA-4 code with detailed chemical kinetics without the need for reducing the reaction mechanism. After validating the code, diesel engine combustion was simulated to investigate combustion and emission characteristics, focusing on soot formation, growth and oxidation at different EGR ratios. To predict soot formation, a gas-phase polycyclic aromatic hydrocarbons (PAH) precursor formation model was coupled with a detailed phenomenological particle formation model, which included soot nucleation from precursors, surface growth/oxidation and particle coagulation. The results indicate that increased soot emission at high EGR ratios is mainly caused by decreased oxidation by oxygen and OH radicals because mixing fuel and gases (including oxygen and OH) has significant effects on reducing the mass of soot.
  • Fast and robust time integration method for stiff chemical kinetic ODEs
    Youhi Morii, Hiroshi Terashima, Mitsuo Koshi, Taro Shimizu, Eiji Shima
    50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference 2014, 01 Jan. 2014
    © 2014 by authors. Published by the American Institute of Aeronautics and Astronautics, Inc. A simple yet robust and fast time integration method is proposed for efficiently solving stiff chemical kinetic ordinary differential equations. The proposed method is based on a general formula which preserves the conservation laws for any integration operators con- structed using the Lagrange multiplier method. A quasi-steady-state approxixmation is used as the integrator. The time step size is automatically controlled by using a Lagrange multiplier so that the error, which is caused by the Lagrange multiplier method, is small. The results of several ignition problems demonstrate the robustness and accuracy of the proposed method in comparison with other integration methods such as a implicit inte- gration method (VODE), a multi time-scalse method (MTS), and a modified CHEMEQ2. The proposed method, named ERENA, provides the fastest performance for the most of conditions used in this study.
  • Numerical study of cryogenic coaxial jet under supercritical condition
    Daiki Muto, Nobuyuki Tsuboi, Hiroshi Terashima
    52nd Aerospace Sciences Meeting, 01 Jan. 2014
    © 2014, American Institute of Aeronautics and Astronautics Inc. All rights reserved. Effects of recess on the mixing of the cryogenic coaxial jet under supercritical conditions were numerically investigated. Recessed injectors have been applied as coaxial injectors of liquid rocket engines because it is expected to improve propellant mixing and combustion efficiency. In the present study, a numerical simulation code was developed to examine jet mixing under the supercritical pressures. For validation of the present method, a two-dimensional planner jet simulation was carried out. The present result showed good agreement with an experimental result. As a preliminary study of coaxial jets, co-planner simulations were performed in a recessed case and an unrecessed case. Large-scale vortical structures were observed in the both cases, and the recessed case showed the larger struc- tures relative to the unrecessed case. This is because of the destabilization mechanism of a recessed region. These instabilities improved entrainments of ambient uid, and as a result, the enhanced jet mixing shortens the jet-core length.
  • Chemical kinetics of hypergolic ignition in hydrazine/nitrogen-dioxide gas mixtures
    Yu Daimon, Hiroshi Terashima, Mitsuo Koshi
    51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013, 19 Aug. 2013
    A detailed chemical kinetic mechanism for hypergolic ignition of N2H4/NO2 gas mixture at low temperatures has been constructed. In this mechanism, the hypergolic ignition is caused by following sequential reactions of H atom abstraction from N2Hm by NO2. N2H4+ NO2= N2H3+ HONO or HNO2(R1) N2H3+ NO2= N2H2+ HONO (R2) N2H2+ NO2= N2H + HONO (R3) N2H + NO2= N2+ HONO (R4) These reactions are exothermic, especially heat release by the reaction (R4) is large because of N2 production. Temperature rise caused by the heat release accelerates the initiation reaction (R1). This 'thermal feedback' is responsible to the hypergolic ignition at ambient temperatures. Since no experimental and theoretical information was available on these reactions, rate coefficients were evaluated on the basis of transition state theory, uni-molecular rate theory, and master equation analysis with quantum chemical calculations of potential energy curves. Results of simulations by using the present mechanism including reactions (R1)-(R4) reasonably agree with existing experimental data. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
  • Characterization of cryogenic nitrogen jet mixings under supercritical pressures
    Hiroshi Terashima, Mitsuo Koshi
    51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013, 19 Aug. 2013
    Two-dimensional planar and three-dimensional round nitrogen jets under supercritical pressures are simulated with a wide range of conditions in order to explore its unique characteristics. A high-order method using a sixth-order compact scheme is applied. The present study parametrically covers two supercritical pressures of 4 MPa and 8 MPa and three jet injection temperatures between a cryogenic jet of 82 K and a warmer jet of 133 K. Unique characteristics are found in both the mean temperature and the temperature fluctuation profiles on the centerline, i.e., slower increase of jet temperature and relatively weak temperature fluctuation, only in case of a near-critical pressure of 4 MPa and a cryogenic jet of 82 K. The temperature profile on the centerline of the cryogenic jet of 82 K under 4 MPa uniquely consists of four characteristic regions. The other conditions show no distinct features. The present study suggests that the distributions of the specific heat capacity at constant pressure help to explain the generation of the unique characteristics on the temperature. © 2013 by the authors.
  • Approach to prevent spurious oscillations in compressible multicomponent flows using high-order methods
    Hiroshi Terashima, Soshi Kawai, Mitsuo Koshi
    American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FEDSM, 01 Dec. 2012
    We present an interface-capturing method for fluid interfaces in compressible multicomponent flows using high-order central-difference-based schemes. Numerical diffusion terms are consistently designed so that the velocity, pressure, and temperature equilibriums are maintained at the fluid interfaces, while serving as an efficient interface-capturing. Advection problems of a contact discontinuity and a material interface shows that 1) the present method maintains the velocity, pressure, and temperature equilibriums at the fluid interfaces (oscillation-free property) and 2) the numerical diffusion terms effectively works for suppressing spurious wiggles of the density or temperature. Comparisons with a conventional fully-conservative approach demonstrates the superiority of the present method in avoiding spurious oscillations. A shock tube problem of two-component gases shows the capability for capturing the shock wave while the velocity and pressure equilibriums are successfully maintained at the contact discontinuity. Copyright © 2012 by ASME.
  • Investigations of trans/supercritical jet mixing using a high-resolution numerical method
    Hiroshi Terashima, Soshi Kawai, Nobuhiro Yamanishi
    41st AIAA Fluid Dynamics Conference and Exhibit, 01 Dec. 2011
    Two-dimensional planar nitrogen jets in supercritical thermodynamic conditions are simulated using a high-resolution numerical method (which consists of a sixth-order compact difference scheme and a localized artificial diffusivity method) with the aim at exploring its unique characteristics. Effects of injection temperature, chamber pressure, and the equation of state on supercritical jet behaviors are investigated. Throughout the investigations, two major unique characteristics are found under the transcritical conditions. One unique characteristic are found in the mean temperature profile, as the slower increase of jet temperature, in the case of transcritical injections. The cause for the unique feature is simply explained by the corresponding temperature-density (T-ρ) diagrams. Another unique feature of supercritical jet flows appears in the generation of different flow scales. The power spectrums and the flow fields quantitatively and qualitatively show the different features of flow scales due to the injection conditions. In the transcritical injection, the production of smaller flow scales is considerably enhanced relative to the other injection cases, due to not only its higher density ratio, but also its abrupt variations (leap) of δρ/δT in the T-ρ diagrams. This study indicates, for the present conditions used, that the unique characteristics of supercritical jet flows appear in the mean temperature distributions and the generation of different flow scales, which are simply yet effectively explained by the T-ρ diagrams. © 2011 by the authors.
  • A front-tracking method with projected interface conditions for compressible multi-fluid flows
    TERASHIMA Hiroshi, TRYGGVASON Gretar
    微粒化シンポジウム講演論文集 = Symposium (ILASS-Japan) on Atomization, 16 Dec. 2009, Japanese
  • Transonic aeroelastic computations of a delta wing configuration with high fidelity equations
    Hiroshi Terashima, Kenji Ono
    Computational Fluid Dynamics 2006 - Proceedings of the Fourth International Conference on Computational Fluid Dynamics, ICCFD 2006, 01 Jan. 2009
  • Reliability of compressible flow/structure coupling method on Cartesian grid with signed distance field
    Hiroshi Terashima, Kenji Ono
    2007 Proceedings of the 5th Joint ASME/JSME Fluids Engineering Summer Conference, FEDSM 2007, 01 Dec. 2007
    A compressible flow solver coupled with moving/deformed geometries on Cartesian grid with Signed Distance Field (SDF) is developed and its capability is investigated through computations of several basic flow fields for future applications with certain reliability. The flow solver is designed so that SDF includes sufficient geometrical information to compute flow fields. Since information of moving/deformed geometries is recognized as a change of the SDF between time steps, the flow solver can be coupled with moving/deformed geometries naturally. The implementation of this solver is simple and easy. No modification is needed in the main part of the flow solver. Furthermore, the interpolation and the corresponding stencils searching process are not required. Several basic flow fields around fixed/moving cylinders and a fixed sphere are computed in order to validate the proposed solver, in which the computed results are compared with available numerical and experimental results. The results demonstrated the method's capability for moderate Reynolds number flows around both of fixed and moving geometries. Based on the results, some criteria and problems for obtaining reliable solution are suggested. Copyright © 2007 by ASME.
  • Effects of number of stores on the transonic flutter characteristics of a delta wing configuration
    Hiroshi Terashima, Kozo Fujii
    34th AIAA Fluid Dynamics Conference and Exhibit, 01 Dec. 2004
    Transonic and supersonic flutter characteristics of a delta wing configuration with external stores are simulated using the fluid/structure coupling method and the effect of the store aerodynamics is investigated. A delta wing with one and two external stores are considered in this study. The stores are located in the rearward of the wing simulating typical high speed aircraft configurations. The computational result shows that the flutter dynamic pressures over all the Mach numbers are reduced by adding external stores for both cases. In addition, the flutter dynamic pressures become much lower when the number of attached external stores is increased. In the case of the single external store, influence of the store aerodynamics can be divided into two regions according to the Mach number. It is found that neglecting the store aerodynamics leads to the overestimation of the flutter dynamic pressures in the supersonic region. In case of two external stores, the store aerodynamics influence on the flutter boundary only at M∞ = 1.22 unlike the case of the single external store. It is shown that the shock wave ahead of the external store influences on the pressure distributions on the lower surface and the location of the shock wave is important for the decision of the flutter boundary. © 2004 by the American Institute of Aeronautics and Astronautics, Inc.
  • Numerical Estimations of Transonic Flutter Phenomena with Fluid/Structure Coupling Method
    TERASHIMA Hiroshi, FUJII Kozo
    年次大会講演論文集 : JSME annual meeting, 20 Sep. 2002, Japanese
    Flutter phenomena for the AGARD445.6 standard aeroelastic wing in the transonic flow are simulated using the fluid/structure coupling method. The effect of time accuracy, number of the inner-iterations and comparison of a fully implicit coupling method with a loosely coupling method are examined. The sufficient number of inner-iterations in time is required for the accurate prediction of time responses when using a large time step. Improvement of the solution time accuracy for the aerodynamic equations is key for accurate aeroelastic computations and the one-step time lag generated in a loosely coupling method does not have an effect in the flutter prediction in transonic flows.
  • 708 Some problems found in the CFD analysis of Space Transportation Systems
    FUJII Kozo, MORIYA Koichiro, TERASHIMA Hiroshi, HORIE Toshiyuki
    Fluids engineering conference ..., 28 Sep. 2001, Japanese
    CFD simulations using three-dimensional compressible Navier-Stokes equations are carried out for the establishment of the reliability of the CFD tools for the aerodynamic evaluation of space transportation systems. Simulations for Apollo-type capsule show that the simulations with typical number of grid points can give us reasonable result and CFD analysis can be a useful tool for the initial estimation of aerodynamic characteristics. Simulations for the FTB configuration show the dependency of the aerodynamic data on the order of accuracy of the simulations. The flow field near the base alters the characteristics. The example for the delta and double-delta wings which may be a candidate for the future TSTO systems shows that the success of the CFD simulations for delta wings does not necessarily justify the CFD results for similar configurations.
  • Flow characteristics of unsteady three-dimensional type IV shock interference
    Satoru Yamamoto, Hiroshi Terashima
    Fluids 2000 Conference and Exhibit, 01 Dec. 2000
    Unsteady three-dimensional hypersonic shock/shock interference flows measured by Berry and Nowak1 are calculated using the shock-vortex capturing method with and without thermochemical nonequilibrium effect. This method contains the 4th-order compact MUSCL TVD scheme, the maximum 2nd-order LU-SGS scheme, and the AUSM-based scheme. Two typical 3-D flows around the forward swept fin at the angle of 0° and -15° are first calculated without reaction. The flow pattern and the shock heating on the body surface are well compared with the experiments. These 3-D flows specified by a high temperature condition are also calculated for resolving the effect of thermochemical nonequilibrium. The two-temperature model based on the Park model is employed for the chemical reaction model. The calculated results show that the increase of temperature changes the type of shock interference because of decreasing the shock standoff distance and also suggest that the shock heating might be very sensitive to the type of shock interference. Finally, unsteady flow characteristics captured both with and without thermochemical nonequilibrium effect are preliminarily expressed. © 2000 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Affiliated academic society

  • AIAA　　　　　　　　　　　　　　　
  • THE JAPAN SOCIETY OF FLUID MECHANICS　　　　　　　　　　　　　　　
  • COMBUSTION SOCIETY OF JAPAN　　　　　　　　　　　　　　　
  • THE JAPAN SOCIETY OF MECHANICAL ENGINEERS　　　　　　　　　　　　　　　
  • THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　　　　　　　　　　　　　　　

Research Themes

  • 超臨界圧燃焼流れ場の高度デジタル予測に資する詳細反応機構-燃焼LES技術の開発
    科学研究費助成事業 基盤研究(B)
    01 Apr. 2021 - 31 Mar. 2024
    寺島 洋史, 河合 宗司
    超臨界圧燃焼流れシミュレーション(超臨界燃焼CFD)を実施するため，まず，熱，輸送物性，そして化学反応モデルに非理想性を考慮した流体物性モデルの開発を行った．非理想性を考慮した物性算出プログラムは，世界で標準的に使用される熱・輸送物性ライブラリChemkinと互換性を持つように設計し，任意反応機構を用いた超臨界燃焼CFD解析が可能となっている．特に本研究では，多くの関連研究で無視されてきた化学反応における非理想性を考慮したモデル構築を行った．化学反応における非理想性は，反応前後のギブス自由エネルギー変化をフガシティーで記述し，最終的には平衡定数の算出において考慮される．高圧水素火炎伝播実験と比較を行い，本モデルが実験で観測された質量燃焼速度の圧力負依存性を再現できることを示した．高圧条件においては，質量燃焼速度予測に理想気体モデルとの差が発生するが，この原因をJoule-Thomson(J-T)効果(エンタルピーの圧力依存性)で説明できることを提示した．例えばアルゴンで希釈されていれば，エンタルピーが負の圧力依存性を持つため，非理想モデルは，理想モデルに比べ低い層流燃焼速度および質量燃焼速度を予測する．J-T効果を用いた非理想性効果の議論はこれまでほとんどなく，本成果は，採択が約35%と競争的で知られている国際燃焼シンポジウムの口頭発表に採択されている．化学反応項LESモデル開発については，これまで開発してきた火炎モデル(LTF)をベースとし，火炎伸張を考慮したモデル拡張(LTF-Beta)を実施した．乱流平面火炎干渉場の解析を通して，wrinkled flame領域では，LTF-BetaがLTFに比べ直接数値解析に近い結果を予測できることを示した．異なる燃焼領域への適用や燃焼速度と火炎伸張率の線形モデルに対するさらなる理論考察が必要であり，継続して研究を実施する．
    日本学術振興会, 基盤研究(B), 北海道大学, 21H01522
  • 詳細反応機構-超臨界圧燃焼LES解析を可能とする乱流燃焼モデルの開発
    科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(A))
    2022 - 2024
    寺島 洋史
    日本学術振興会, 国際共同研究加速基金(国際共同研究強化(A)), 北海道大学, 21KK0250
  • Challenges for high-fidelity turbulent combustion simulation based on detailed reaction mechanisms
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)
    28 Jun. 2019 - 31 Mar. 2022
    Kawai Soshi
    This study investigated a high-fidelity turbulent combustion LES method based on detailed reaction mechanisms that reproduce turbulent combustion phenomena using coarse grids. To establish the high-fidelity LES method, we first proposed the localized thickened flame (LTF) model that spatially expands the flame thickness while maintaining the accurate laminar burning velocity and auto-ignition without changing the chemical species distributions inside the flame. Then, based on the LTF model, the turbulent combustion LES method that models the fame curvature effects was proposed and validated through the turbulence and flame interaction problem.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Tohoku University, 19K21927
  • Modeling for multi-component flows and combustion dynamics under supercritical pressure environments
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    01 Apr. 2017 - 31 Mar. 2020
    Terashima Hiroshi
    This study has developed a simulation method for combustion and multi-component flow dynamics under supercritical pressures. The method introduced the non-ideal thermodynamic and transport property models to consider peculiar behaviors that appear in supercritical pressures. All the models were fully validated in comparison with experimental or reference data. The flame propagation problems under supercritical pressures demonstrated that the non-ideal effects in the diffusion coefficient are the most influential for the prediction of laminar flame speeds. Regarding thinner flame in higher-pressure conditions, we have developed a new flame model, with which the flame propagation behavior under elevated pressure conditions was successfully captured even on coarser grids. Besides, we constructed a non-ideal fluid library, with which the non-ideal thermodynamic and transport properties are easily obtained in arbitrary simulation programs.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 17K06939
  • Combustion-reaction database specialized for accidental fire/explosion simulations
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2015 - 31 Mar. 2018
    Kuwana Kazunori
    The objective of this study was to develop a combustion-reaction database specialized for numerical simulations of fire/explosion phenomena. Kinetic parameters of global reaction models were first determined based on the results of experiments and 1-D detailed-reaction simulations. Numerical simulations were then conducted using the obtained global models and other reduced reaction models to compare with the results of experiments or detailed-reaction simulations. A methodology was finally discussed to select the optimal reaction model depending on the local condition.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Yamagata University, 15H02977
  • Investigation of Effects of Coaxial Injector Shape on Mixing, Diffusion, and Combustion Process of Cryogenic High-Pressure Propellant
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2015 - 31 Mar. 2018
    Tsuboi Nobuyuki, KOSHI Mitsuo, HAYASHI A. Koichi, TOKUMASU Takashi, TSUDA Shinichi, TERASHIMA Hiroshi, SHIMIZU Taro, ASAHARA Makoto, MORII Youhi, NAGASHIMA Hiroki, MUTO Daiki, OZAWA Kohei
    The numerical and experimental studies on the cryogenic flow under the transcritical and supercritical pressures are performed in order to understand the thermodynamic characteristics and fluid dynamics. The coaxial cryogenic nitrogen jet flows under the supercritical pressure are simulated using ILES/RANS hybrid method. The mean inner jet lengths of the present simulations agree well with those of the previous experiments and numerical simulations. As for the multi-species flow simulations, the numerical method using a hybrid method between the energy equation and pressure-evolution-equation, which is able to prevent from pressure oscillations in the flow, is developed. In the experiments, visualization data and temperature profiles in the cryogenic nitrogen channel flow are measured under the subcritical and supercritical pressures.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Kyushu Institute of Technology, 15H04202
  • Research on dynamic design method for achieving both high efficiency and environmental performance of small energy conversion equipment
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    01 Apr. 2014 - 31 Mar. 2018
    Kaneko Shigehiko
    Toward utilization of biofuel and realization of eco-mobility, compatibility of the high efficiency of small energy conversion equipment and environmental performance is an essential condition. The problems to be solved in this study are ① a gas turbine for small power generation operated by natural gas, biogas, coal gas, etc. as fuel, ② a reciprocating engine for dual fuel automobiles using both biogas and liquid fuel as fuel, ③ jet fuel and biofuel for small turbojet engines to be used as fuel.
    In each problem, barriers for achieving both high efficiency and environmental performance embedded are ① measures against combustion vibration, ② real-time control algorithm with light calculation load, ③ development of noise reduction device released from a nozzle. We proposed a solution to such dynamic problems inherent in corresponding energy converting devices from a new viewpoint involving chemical reactions.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 26289053
  • An approach of modifying the governing equations in a physically-consistent manner for modeling of turbulent mixing and combustion
    Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    01 Apr. 2015 - 31 Mar. 2017
    Kawai Soshi
    In this study, an accurate and robust numerical modeling for simulating realistic chemically reacting flow problems using detailed chemical kinetics was studied. Our approach is to couple our idea of modifying the governing equations in a physically-consistent manner and the concept of artificially thickened flame modeling that maintains physical laminar flame speed while artificially thickening flames. Also, by considering the extension of our approach to applying a high-order accurate numerical method, we proposed flux-based high-order accurate Pade-type filters that can satisfy the conservation law of each specie at the order of the machine zero level, something that existing Pade-type filters fail to do.
    Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Tohoku University, 15K14258
  • An efficient methodology for combustion flow simulations with large detailed chemical kinetics
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    2014 - 2016
    Terashima Hiroshi, KOSHI Mitsuo, MORII Youhi
    An efficient methodology for simulations of reactive flows (CFD) with large detailed chemical kinetics has been successfully proposed. The present method consists of a fast explicit time integration method for stiff chemical reaction equations and a species bundling technique for efficient calculations of transport properties of mixture. The present method, in particular, the fast explicit time integration method, provides much faster performance with the order of two or three when compared to a conventional approach, enabling an efficient application of large detailed chemical kinetics in CFD simulations. The method has been successfully applied to a wide range of combustion problems such as knocking phenomena of n-heptane (373 chemical species and 1071 reactions) in internal combustion engines, providing the detailed mechanism of strong pressure wave generation and development associated with end-gas autoignition.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), 東京大学, Competitive research funding, 26390128
  • Scientific Principle on Risk Analysis of Gas Explosions
    Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    2011 - 2014
    DOBASHI Ritsu, TERASHIMA Hiroshi, KUWANA Kazunori, MOGI Toshio, KOSHI Mitsuo
    Studies were conducted to promote scientific understanding on occurrence probability (explosion limit) and consequence (consequent damages) of gas explosions. About the explosion limit, it was found that the limit and its dependence on conditions can be appropriately predicted by considering adequate reaction scheme. About the consequence analysis, precious evaluation method of Markstein number, which is important to estimate flame front instability, has been newly developed. Also, it was found a large scale flame is propagating in self-similar manner and its flame area is growing in fractal manner. The mechanism of accelerating development of consequent damages can be understood. These results highly contribute to promote scientific predictions of gas explosion risks.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), The University of Tokyo, Competitive research funding, 23241051
  • Development of reduction method of detailed chemical kinetics and its application to reactive flow simulation
    Grants-in-Aid for Scientific Research(基盤研究(B))
    2011 - 2013
    Mitsuo KOSHI
    Reactive flow analysis for complex system such as automobile engine knocking and vibratory combustion in gas turbine needs fluid dynamic simulation coupled with detailed chemical kinetics. Because of very large numbers of chemical species involved in combustion, such reactive flow analysis is extremely difficult. We successfully developed a new method for the reduction of number of chemical species. In addition, an ultra fast solver of chemical kinetic equations is also developed and implemented into compressible CFD (computer fluid dynamics) code. As a result, reactive flow analysis now become possible for automobile engine knocking.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 東京大学->横浜国立大学, Competitive research funding, 23360095
  • Research of Combustion Dynamics on Cryogenic Flow under Supercritical Pressure
    Grants-in-Aid for Scientific Research(基盤研究(B))
    2011 - 2013
    Nobuyuki TSUBOI, Susum TERAMOTO, Mitsuo KOSHI, Hayashi HAYASHI, Takashi TOKUMASU, Shinichi TSUDA, Kazuya SHIMIZU, Taro SHIMIZU, Hiroumi TANI, Makoto ASAHARA, Youhi MORII
    The numerical and experimental studies on the cryogenic flow under the supercritical pressure are performed in order to understand the thermodynamic characteristics and fluid dynamics. The averaged density distributions of the mono-axial nitrogen jet flow under the supercritical pressure using RANS simulations agree well with the experimental data. The preconditioning method including multi-species mass-conservation equations was developed to capture the unsteady feature near the shear layer in the low-speed H2/O2 shear flow. As for LES simulations, the cryogenic nitrogen/nitrogen mixing layers in ideal-gas and transcritical conditions were also simulated. The results show that the effects of the pseudo-critical temperature are small on the turbulent eddy structure. In the experiment for the cryogenic nitrogen jet under the transcritical pressure, the temperature gradient along the symmetric line becomes small near the pseudo-critical temperature.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 九州工業大学, Competitive research funding, 23360380
  • A front-tracking method for fluid interfaces in high-speed compressible flows
    Grants-in-Aid for Scientific Research(若手研究(B))
    2011 - 2012
    Hiroshi TERASHIMA
    A front tracking method for compressible multi-fluid flows is presented where marker points are used both for tracking fluid interfaces and also for constructing the Riemann problem on the interfaces. The Riemann problem between two fluid phases (defined in the interface normal direction) is solved using the exact Riemann solver on the maker points. The solutions are projected onto fixed grid points and then extrapolated into the corresponding ghost fluid regions, as in the ghost fluid method. The proposed procedures are designed to be consistent in any dimensions and to be simple to implement. Several multi-fluid problems, including the breakup of a water cylinder induced by the passage of a shock wave, were computed in order to demonstrate the capability of the new method.
    Ministry of Education, Culture, Sports, Science and Technology, 若手研究(B), 独立行政法人宇宙航空研究開発機構->東京大学, Principal investigator, Competitive research funding, 23760079
  • 自己接触を伴う薄膜折りたたみ展開構造物のボディダイナミクスシミュレーション
    科学研究費補助金(若手研究(B))
    2006 - 2008
    寺島 洋史
    本研究は,AirbagやParachuteといった流体と干渉する薄膜展開構造物のダイナミクスシミュレーションを行う数値手法の開発と設計への応用を目的とする.流体解析には,大変形薄膜物体を容易かつロバストに扱うため直交格子を用い,構造解析には幾何学的非線形性を考慮した有限要素法を採用した.今年度は,直交格子を用いた流体解析手法の開発と,流体と移動剛体が連成した流体剛体連成解析手法を開発し,その信頼性を評価した.本手法は以下の特長を持つ:1)距離関数場(Signed Distance Filed : SDF)を使用2)プログラムの修正は境界条件部分のみで,オリジナルソルバーからの修正が非常に容易3)鏡面境界条件で見られる境界付近の物理量内挿処理とそれに伴う点探索処理が無い4)SDF情報の変化がダイレクトに物体移動の情報を表し,流体構造連成問題を合理的に扱える特に3)は移動変形物体を扱う際に有利な点である.直交格子の解析でしばしば問題となるのが計算結果の信頼性である.信頼性を検証するため,基本的な流れ場(円柱,球,振動円柱)のシミュレーションを行い,実験や他の計算と比較を行った.固定円柱と球の計算結果から,レイノルズ数500までではあるが,他の結果と良い一致を得た.また,格子解像度の影響を調べ,予想される境界層厚さに10点程度の格子点を配置することにより,信頼性ある解が得られることを示した.これは今後の解析における格子解像度選択の指標となる.振動円柱の解析では,SDFの変化をベースとした本手法が移動物体のシミュレーションに対して有効であることを示し,また,固定円柱の流れ場に比べ,力の振幅や位相を正確に求める上で格子解像度が重要であることを明らかにした.また,粗い格子を用いると,力の時間履歴に虚偽振動が発生することがわかった.この原因は今後の課題である.
    文部科学省, 若手研究(B), 独立行政法人理化学研究所, Principal investigator, Competitive research funding, 18760068