Updated on 2024/02/18

写真a

 
Atsushi Sekimoto
 
Organization
Faculty of Environmental, Life, Natural Science and Technology Associate Professor
Position
Associate Professor
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Degree

  • Ph. D ( 2011.3   Osaka University )

Research Interests

  • Turbulence

  • data-driven science

  • thermal fluid mehcanics

Research Areas

  • Informatics / Computational science

  • Natural Science / Mathematical physics and fundamental theory of condensed matter physics

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Fluid engineering

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Thermal engineering

Education

  • Osaka University   基礎工学研究科   機能創成専攻

    - 2010.3

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    Country: Japan

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  • Osaka University   基礎工学研究科   機能創成専攻

    - 2007.3

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    Country: Japan

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  • Osaka University   基礎工学部   システム科学科 機械科学コース

    - 2005.3

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Research History

  • Okayama University   Faculty of Environmental, Life, Natural Science / School of Engineering, Mathematical and Data Sciences   Associated Professor

    2023.4

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  • Okayama University   Faculty of Environmental and life science / School of Engineering, Mathematical and Data Scienses   Associate Professor

    2021.4 - 2023.3

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    Country:Japan

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  • Osaka University   Graduate School of Engineering Science Department of Materials Engineering Science Division of Chemical Engineering   Assistant Professor

    2017.9 - 2021.3

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    Country:Japan

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  • Monash University, Research Fellow

    2016.4 - 2017.9

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  • Universidad Politécnica de Madrid, Research Fellow

    2011.7 - 2016.1

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  • Advanced Knowledge Laboratory Inc. (AKL)

    2010.4 - 2011.3

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  • Research Fellow of the Japan Society for the Promotion of Science (DC2)

    2009.4 - 2010.3

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Professional Memberships

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Committee Memberships

  • 日本流体力学会   学会誌「ながれ」編集委員  

    2022.4   

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    Committee type:Academic society

  • 日本流体力学会   学会誌「ながれ」編集委員  

    2022.4   

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  • 化学工学会関西支部若手の会「CES21」   企画運営  

    2020.4 - 2021.3   

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    Committee type:Academic society

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  • 化学工学会   熱工学部会役員 企画幹事, ポスター委員  

    2019.4   

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  • 化学工学会   化学工学会誌トピックス委員(熱工学)  

    2019.1   

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Papers

  • A Numerical Study on the Exact Onset of Flow Instabilities in Thermo-Solutal Marangoni Convection Driven by Opposing Forces in a Half-Zone Liquid Bridge under Zero Gravity Reviewed

    Radeesha Laknath, Agampodi Mendis, Atsushi Sekimoto, Yasunori Okano, Hisashi Minakuchi, Sadik Dost

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN   54 ( 8 )   424 - 430   2021.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Society of Chemical Engineers, Japan  

    DOI: 10.1252/jcej.21we041

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  • Estimation of the diffusion coefficient of GaSb in InSb melt using Bayesian optimization and the ISS experimental results Reviewed

    Rachid Ghritli, Yasunori Okano, Yuko Inatomi, Atsushi Sekimoto, Sadik Dost

    Journal of Crystal Growth   573   126280 - 126280   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    The diffusion coefficient of GaSb in InSb melt was estimated by using the microgravity experimental results performed onboard the International Space Station (ISS), where the effect of natural convection is minimized. We numerically investigated the transport phenomena during InGaSb crystals growth via a vertical gradient freezing method and it was deduced that the growth rate is dominated by the solute diffusion in the melt. Furthermore, the crystal growth rate was well explained by adopting a diffusion coefficient with function of GaSb concentration, obtained by analyzing the available experimental results and utilizing machine learning and Bayesian optimization methods. These results also contribute to further understanding of crystal growth on the ground.

    DOI: 10.1016/j.jcrysgro.2021.126280

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  • The Relative Contribution of Solutal Marangoni Convection to Thermal Marangoni Flow Instabilities in a Liquid Bridge of Smaller Aspect Ratios under Zero Gravity Reviewed

    Radeesha Laknath Agampodi Mendis, Atsushi Sekimoto, Yasunori Okano, Hisashi Minakuchi, Sadik Dost

    Crystals   11 ( 2 )   116 - 116   2021.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    The effect of solutal Marangoni convection on flow instabilities in the presence of thermal Marangoni convection in a Si-Ge liquid bridge with different aspect ratios As has been investigated by three-dimensional (3D) numerical simulations under zero gravity. We consider a half-zone model of a liquid bridge between a cold (top plane) and a hot (bottom plane) disks. The highest Si concentration is on the top of the liquid bridge. The aspect ratio (As) drastically affects the critical Marangoni numbers: the critical solutal Marangoni number (under small thermal Marangoni numbers (MaTAs≲1800)) has the same dependence on As as the critical thermal Marangoni number (under small solutal Marangoni numbers (400≲MaCAs≲800)), i.e., it decreases with increasing As. The azimuthal wavenumber of the traveling wave mode increases as decreasing As, i.e., larger azimuthal wavenumbers (m=6,7,11,12, and 13) appear for As=0.25, and only m=2 appears when As is one and larger. The oscillatory modes of the hydro waves have been extracted as the spatiotemporal structures by using dynamic mode decomposition (DMD). The present study suggests a proper parameter region of quiescent steady flow suitable for crystal growth for smaller aspect ratios of the liquid bridge.

    DOI: 10.3390/cryst11020116

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  • Explainable machine learning for the analysis of transport phenomena in top-seeded solution growth of SiC single crystal Invited Reviewed

    Yuto TAKEHARA, Atsushi SEKIMOTO, Yasunori OKANO, Toru UJIHARA, Sadik DOST

    Journal of Thermal Science and Technology   16 ( 1 )   JTST0009 - JTST0009   2021

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japan Society of Mechanical Engineers  

    DOI: 10.1299/jtst.2021jtst0009

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  • Numerical simulation of thermal-solutal Marangoni convection in a shallow rectangular cavity with mutually perpendicular temperature and concentration gradients Reviewed

    Jiangao Zhang, Atsushi Sekimoto, Yasunori Okano, Sadik Dost

    Physics of Fluids   32 ( 10 )   102108 - 102108   2020.10

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:AIP Publishing  

    DOI: 10.1063/5.0026080

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  • Optimal Control of SiC Crystal Growth in the RF-TSSG System Using Reinforcement Learning Reviewed

    Lei Wang, Atsushi Sekimoto, Yuto Takehara, Yasunori Okano, Toru Ujihara, Sadik Dost

    Crystals   10 ( 9 )   791 - 791   2020.9

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    We have developed a reinforcement learning (RL) model to control the melt flow in the radio frequency (RF) top-seeded solution growth (TSSG) process for growing more uniform SiC crystals with a higher growth rate. In the study, the electromagnetic field (EM) strength is controlled by the RL model to weaken the influence of Marangoni convection. The RL model is trained through a two-dimensional (2D) numerical simulation of the TSSG process. As a result, the growth rate under the control of the RL model is improved significantly. The optimized RF-coil parameters based on the control strategy for the 2D melt flow are used in a three-dimensional (3D) numerical simulation for model validation, which predicts a higher and more uniform growth rate. It is shown that the present RL model can significantly reduce the development cost and offers a useful means of finding the optimal RF-coil parameters.

    DOI: 10.3390/cryst10090791

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  • Global Linear Stability Analysis of Thermo-solutal Marangoni Convection in a Liquid Bridge Under Zero Gravity Reviewed

    Radeesha Laknath Agampodi Mendis, Atsushi Sekimoto, Yasunori Okano, Hisashi Minakuchi, Sadik Dost

    Microgravity Science and Technology   32 ( 4 )   729 - 735   2020.8

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Springer Science and Business Media LLC  

    DOI: 10.1007/s12217-020-09798-9

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    Other Link: https://link.springer.com/article/10.1007/s12217-020-09798-9/fulltext.html

  • The Numerical Estimation of Mass Transfer Coefficient of Oxygen in the Large-Scale Suspension Culture of iPS Cells Reviewed

    R Isobe, Y Kanemaru, A Sekimoto, Y Okano, M Kino-Oka

    IOP Conference Series: Materials Science and Engineering   778 ( 1 )   012030 - 012030   2020.5

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IOP Publishing  

    © 2020 IOP Publishing Ltd. In order to practically apply induced pluripotent stem (iPS) cells to regenerative medicine, a large amount of undifferentiated iPS cells should be produced by using an automated/scaled-up suspension culture system. However, in large-scale culture, oxygen supply to iPS cells away from the gas-liquid interface can be insufficient. In this numerical study, the oxygen supply performance is quantitatively evaluated by estimating the volumetric mass transfer coefficient of oxygen in the suspension culture of iPS cells. And, focusing on shaking culture, where shear stress that causes death or differentiation of iPS cells is relatively reduced, we compare two different shaking methods: one direction rotation (ODR) and periodic alternate rotation (PAR). The validity of the volumetric mass transfer coefficient calculation is confirmed by comparison with the experiment. The PAR method is superior to the ODR method in terms of oxygen supply because of higher turbulence intensities, but it is much less energy efficient than the ODR method. In the ODR method, the cell size is thought to be non-uniform since iPS cells are aggregated due to cell sedimentation. On the other hand, in the PAR method, cell sedimentation is suppressed by controlling the Froude number (Fr).

    DOI: 10.1088/1757-899x/778/1/012030

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    Other Link: https://iopscience.iop.org/article/10.1088/1757-899X/778/1/012030

  • Characterization of the thermal and solutal Marangoni flows of opposite directions developing in a cylindrical liquid bridge under zero gravity Reviewed

    Physics of Fluids   32   034104   2020.3

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1063/1.5142071

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  • Numerical Study of Three-Dimensional Melt Flows during the TSSG Process of SiC Crystal for the Influence of Input Parameters of RF-Coils and an External Rotating Magnetic Field Reviewed

    Lei Wang, Yuto Takehara, Atsushi Sekimoto, Yasunori Okano, Toru Ujihara, Sadik Dost

    Crystals   10 ( 2 )   111 - 111   2020.2

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Three-dimensional numerical simulations were conducted for the Top-Seeded Solution Growth (TSSG) process of silicon carbide (SiC) crystals. We investigated the influence of coils frequency and peak current, and an applied rotating magnetic field (RMF) on the melt flow developing in this system. Numerical simulation results show that the Marangoni flow in the melt becomes stronger at higher coils frequencies due to the decreasing coils-induced electromagnetic field strength. Results also show that the use of external RMF may improve supersaturation uniformity along the seed if it is properly adjusted with respect to the coils-induced electromagnetic field strength. Furthermore, it is predicted that the application of RMF and seed rotation in the same direction may enhance supersaturation below the seed.

    DOI: 10.3390/cryst10020111

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  • Bayesian Optimization for a High-and Uniform-Crystal Growth Rate in the Top-Seeded Solution Growth Process of Silicon Carbide under Applied Magnetic Field and Seed Rotation Reviewed

    Y Takehara, A Sekimoto, Y Okano, T Ujihara, S Dost

    Journal of Crystal Growth   532   125437   2020.2

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jcrysgro.2019.125437

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  • Analysis of the factors contributing to the skin friction coefficient in adverse pressure gradient turbulent boundary layers and their variation with the pressure gradient Reviewed

    Shevarjun Senthil, Vassili Kitsios, Atsushi Sekimoto, Callum Atkinson, Julio Soria

    International Journal of Heat and Fluid Flow   82   108531 - 108531   2020.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.ijheatfluidflow.2019.108531

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  • Numerical Investigation of Gas-Liquid Two-Phase Flow in a Stirred Tank Invited Reviewed

    Nao Ishida, Al Abri Mohammed, Atsushi Sekimoto, Yasunori Okano, Shinya Abe, Kosuke Tanaka

    Lecture Notes in Networks and Systems   301 - 309   2020

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    Language:English   Publishing type:Part of collection (book)   Publisher:Springer International Publishing  

    DOI: 10.1007/978-3-030-36841-8_29

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  • Outer scaling of self-similar adverse-pressure-gradient turbulent boundary layers

    arXiv:1912.05143   2019.12

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  • Numerical investigation of particle dispersion in the preprocessing stage for a static cell cultivation Reviewed

    Atsushi Sekimoto, Yoshiki Kanemaru, Yasunori Okano, Kei Kanie, Ryuji Kato, Masahiro Kino-oka

    REGENERATIVE THERAPY   12   83 - 87   2019.12

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER  

    In order to produce high-quality cells in a static culture, the initial placement of the cells is one of the most important factors. Dense distribution of the cells increases the risk of cell death. Thus, the cells need to be uniformly distributed during the preprocessing of a static culture. This process depends on the operator's experience and has not been standardized. In this study, we have performed numerical simulations to investigate the efficiency of cell dispersion by using OpenFOAM. The numerical domain is a square-shaped dish. Two shaking methods, one-direction and multi-direction reciprocal shaking, were considered and calculations were conducted under five oscillation frequencies. The cell colony was assumed as a solid spherical particle. The initial particles were densely positioned at the center. The numerical result showed that the multi-direction reciprocal shaking was more effective to disperse the particles than the one-direction reciprocal shaking. In addition, at a low frequency, almost all particles sank to the bottom and hardly dispersed. These results indicate that strong fluctuations can lift particles from the bottom and that frequent changes in the flow direction make for more even distribution. (C) 2019, The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.

    DOI: 10.1016/j.reth.2019.04.003.

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  • Three-dimensional numerical analysis of Marangoni convection occurring during the growth process of SiC by the RF-TSSG method Reviewed

    L. Wang, T. Horiuchi, A. Sekimoto, Y. Okano, T. Ujihara, S. Dost

    Journal of Crystal Growth   520   72 - 81   2019.8

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jcrysgro.2019.05.017

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  • Modal analysis of coherent structures in self-similar turbulent boundary layers with adverse pressure gradient Reviewed

    Jens S. Müller, Kilian Oberleithner, Michael P. Eisfelder, Atsushi Sekimoto, Abel-John Buchner, Vassili Kitsios, Callum Atkinson, Julio Soria

    2019.8

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  • The three-dimensional structures in turbulent Couette-Poiseuille flows on the verge of separation Reviewed

    Zehuan Wu, Callum Atkinson, Julio Soria, Atsushi Sekimoto

    Proc. 11th International Symposium on Turbulence and Shear Flow Phenomena   2019.8

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  • Adjoint-based sensitivity analysis for the optimal crucible temperature profile in the RF-Heating TSSG-SiC crystal growth process Reviewed

    Takashi Horiuchi, Lei Wang, Atsushi Sekimoto, Yasunori Okano, Toru Ujihara, Sadik Dost

    Journal of Crystal Growth   517   59 - 63   2019.7

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jcrysgro.2019.04.001

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  • Effect of Thin and Rough Layers of Porous Materials on Drag Reviewed

    Petya Valentinova Stoyanova, Lei Wang, Atsushi Sekimoto, Yasunori Okano, Youhei Takagi

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN   52 ( 6 )   493 - 500   2019.6

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Society of Chemical Engineers, Japan  

    DOI: 10.1252/jcej.18we318

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  • Numerical investigation of the nano-scale solutal Marangoni convections Invited Reviewed

    Y. Imai, T. Yamamoto, A. Sekimoto, Y. Okano, R. Sato, Y. Shigeta

    Journal of the Taiwan Institute of Chemical Engineers   98   20 - 26   2019.5

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jtice.2018.05.015

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  • The Effect of Crucible Rotation and Crucible Size in Top-Seeded Solution Growth of Single-Crystal Silicon Carbide Reviewed

    Takashi Horiuchi, Lei Wang, Atsushi Sekimoto, Yasunori Okano, Takuya Yamamoto, Toru Ujihara, Sadik Dost

    Crystal Research and Technology   54 ( 5 )   1900014 - 1900014   2019.5

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Wiley  

    DOI: 10.1002/crat.201900014

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  • Numerical Investigation of the Effect of Heating Rate on InGaSb Crystal Growth under Zero-Gravity Reviewed

    Xin Jin, Atsushi Sekimoto, Yasunori Okano, Takuya Yamamoto, Yasuhiro Hayakawa, Yuko Inatomi, Sadik Dost

    MICROGRAVITY SCIENCE AND TECHNOLOGY   31 ( 4 )   377 - 380   2019.4

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER  

    In order to determine the optimum heating rate for the planned microgravity experiments on the International Space Station (ISS), axisymmetric 2D numerical simulations were performed under the zero-gravity condition to investigate the effect of heating rate on the dissolution process of the seed and feed crystals in a sandwich system of InGaSb. The simulation results showed that the dissolution lengths of the seed and feed crystals are strongly affected by heating rate. A higher heating rate leads to larger feed and seed dissolutions. Simulation results suggest that the microgravity experiments on the ISS should not adopt a heating rate higher than 3.6 K/h in order to avoid a complete dissolution of the feed and/or seed crystals in this sandwich system.

    DOI: 10.1007/s12217-019-9698-x

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  • Numerical simulation of particle dispersion in a pre-processing of a static culture Reviewed

    Yoshiki Kanemaru, Atsushi Sekimoto, Yasunori Okano, Kei Kanie, Ryuji Kato, Masahiro Kino-oka

    REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING (RSCE)   268   01001 - 01001   2019.2

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:EDP Sciences  

    For producing high-quality induced pluripotent stem (iPS) cells in a static culture, initial placement of cells is one of the most important factors. Dense distribution of cells increases the risk of cell death. Thus, the cells need to be uniformly distributed during the preprocess of a static culture. This process depends on the operator’s experiences and has not been standardized. In this study, the authors have performed numerical simulations to investigate the efficient of cell dispersion by using OpenFOAM. The numerical domain is a square-shaped dish. Two shaking methods, one-direction and multi-direction reciprocal shaking, were considered and calculations were conducted under five oscillation frequencies. The cell colony was assumed as a solid spherical particle. The initial particles were densely positioned at the center. The numerical result showed that the multi-direction reciprocal shaking was more effective to disperse the particles than the one-direction reciprocal shaking. In addition, almost all particles at low frequency sank to the bottom and hardly dispersed. These results indicate that strong fluctuations can lift particles from the bottom, and frequent change of flow direction makes distribution area wide.

    DOI: 10.1051/matecconf/201926801001

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  • Numerical optimization of the shaking speed suspension culture of iPS cells Reviewed

    K. Elvitigala, Y. Kanemaru, M. Yano, A. Sekimoto, Y. Okano, M. Kino-Oka

    Proc. of the 29 th International Symposium on Transport Phenomena   2018.12

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  • The numerical study of coexistence effect of thermal and solutal Marangoni convections in a liquid bridge Reviewed

    Chihao Jin, Atsushi Sekimoto, Yasunori Okano, Hisashi Minakuchi

    Lecture Notes in Network and Systems 53, Recent Advances in Technology Research and Education, Proc. 17th International Conf. on Global Research and Education, Inter-Academia-2018   244 - 252   2018.12

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  • Quadrant analysis and integral length scale of Couette-Poiseuille flows on the verge of separation Reviewed

    Zehuan Wu, Atsushi Sekimoto, Callum Atkinson, Julio Soria

    Proceedings of 21th Australasian Fluid Mechanics Conference   2018.12

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  • Stability of a self-similar adverse pressure gradient turbulent boundary layer Reviewed

    M. P. Eisfelder, J.S. Muller, A. Sekimoto, A-J. Buchner, V. Kitsios, C. Atkinson, K. Overleithner, J. Soria

    2018.12

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  • Numerical Simulation of Shaking Optimization in a Suspension Culture of iPS Cells Reviewed

    K. Elvitigala, Y. Kanemaru, M. Yano, A. Sekimoto, Y. Okano, M. Kino-Oka

    Lecture Notes in Network and Systems 53, Recent Advances in Technology Research and Education, Proc. 17th International Conf. on Global Research and Education, Inter-Academia-2018   283 - 289   2018.12

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  • Numerical investigation of the effect of static magnetic field on the TSSG growth of SiC

    Lei Wang, Takashi Horiuchi, Atsushi Sekimoto, Yasunori Okano, Toru Ujihara, Sadik Dost

    Journal of Crystal Growth   498   140 - 147   2018.9

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jcrysgro.2018.06.017

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  • Near-wall structures in Couette- Poiseuille flows at the verge of separation Reviewed

    Zehuan Wu, Atsushi Sekimoto, Callum Atkinson, Julio Soria

    Proc. 11 th Australasian Heat and Mass Transfer Conference   2018.7

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  • Characterisation of minimal-span plane Couette turbulence with pressure gradients Reviewed

    Atsushi Sekimoto, Callum Atkinson, Julio Soria

    Journal of Physics: Conference Series   1001 ( 1 )   012020   2018.4

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Institute of Physics Publishing  

    The turbulence statistics and dynamics in the spanwise-minimal plane Couette flow with pressure gradients, so-called, Couette-Poiseuille (C-P) flow, are investigated using direct numerical simulation. The large-scale motion is limited in the spanwise box dimension as in the minimal-span channel turbulence of Flores &amp
    Jiménez (Phys. Fluids, vol. 22, 2010, 071704). The effect of the top wall, where normal pressure-driven Poiseuille flow is realised, is distinguished from the events on the bottom wall, where the pressure gradient results in mild or almost-zero wall-shear stress. A proper scaling of turbulence statistics in minimal-span C-P flows is presented. Also the 'shear-less' wall-bounded turbulence, where the Corrsin shear parameter is very weak compared to normal wall-bounded turbulence, represents local separation, which is also observed as spanwise streaks of reversed flow in full-size plane C-P turbulence. The local separation is a multi-scale event, which grows up to the order of the channel height even in the minimal-span geometry.

    DOI: 10.1088/1742-6596/1001/1/012020

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  • Reynolds stress structures in a self-similar adverse pressure gradient turbulent boundary layer at the verge of separation. Invited Reviewed

    C. Atkinson, A. Sekimoto, J. Jiménez, J. Soria

    Journal of Physics: Conference Series   1001   012001 - 012001   2018.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP Publishing  

    DOI: 10.1088/1742-6596/1001/1/012001

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    Other Link: http://stacks.iop.org/1742-6596/1001/i=1/a=012001?key=crossref.a81588c228e2eced6998e31d1def2a7c

  • Direct numerical simulation of a self-similar adverse pressure gradient turbulent boundary layer at the verge of separation Reviewed

    Vassili Kitsios, Atsushi Sekimoto, Callum Atkinson, Juan A. Sillero, Guillem Borrell, Ayse G. Gungor, Javier Jiménez, Julio Soria

    Journal of Fluid Mechanics   829   392 - 419   2017.10

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    The statistical properties are presented for the direct numerical simulation<br />
    (DNS) of a self-similar adverse pressure gradient (APG) turbulent boundary<br />
    layer (TBL) at the verge of separation. The APG TBL has a momentum thickness<br />
    based Reynolds number range from $Re_{\delta_2}=570$ to $13800$, with a<br />
    self-similar region from $Re_{\delta_2} = 10000$ to $12300$. Within this domain<br />
    the average non-dimensional pressure gradient parameter $\beta=39$, where for a<br />
    unit density $\beta=\delta_1 P_e^\prime / \tau_w$, with $\delta_1$ the<br />
    displacement thickness, $\tau_w$ the mean shear stress at the wall, and<br />
    $P_e^\prime$ the farfield pressure gradient. This flow is compared to previous<br />
    zero pressure gradient (ZPG) and mild APG TBL ($\beta=1$) results of similar<br />
    Reynolds number. All flows are generated via the DNS of a TBL on a flat surface<br />
    with farfield boundary conditions tailored to apply the desired pressure<br />
    gradient. The conditions for self-similarity, and the appropriate length and<br />
    velocity scales are derived. The mean and Reynolds stress profiles are shown to<br />
    collapse when non-dimensionalised on the basis of these length and velocity<br />
    scales. As the pressure gradient increases the flow has properties less like a<br />
    ZPG TBL and more akin to a free shear layer.

    DOI: 10.1017/jfm.2017.549

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  • Intense focal and Reynolds stress structures of a self-similar adverse pressure gradient turbulent boundary layer Reviewed

    A. Sekimoto, V. Kitsios, C. Atkinson, J. Jiménez, J. Soria

    Proc. of 10th Symp. on Turbulence and Shear Flow Phenomena   2017.10

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  • Vertically localised equilibrium solutions in large-eddy simulations of homogeneous shear flow Reviewed

    Atsushi Sekimoto, Javier Jimenez

    JOURNAL OF FLUID MECHANICS   827   225 - 249   2017.9

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    Unstable equilibrium solutions in a homogeneous shear flow with sinuous (streamwise-shift-reflection and spanwise-shift-rotation) symmetry are numerically found in large-eddy simulations (LES) with no kinetic viscosity. The small-scale properties are determined by the mixing length scale l(S) used to define eddy viscosity, and the large-scale motion is induced by the mean shear at the integral scale, which is limited by the spanwise box dimension L-z. The fraction R-S = L-z = l(S), which plays the role of a Reynolds number, is used as a numerical continuation parameter. It is shown that equilibrium solutions appear by a saddle-node bifurcation as R-S increases, and that the flow structures resemble those in plane Couette flow with the same sinuous symmetry. The vortical structures of both lower-and upper-branch solutions become spontaneously localised in the vertical direction. The lower-branch solution is an edge state at low R-S, and takes the form of a thin critical layer as R-S increases, as in the asymptotic theory of generic shear flow at high Reynolds numbers. On the other hand, the upper-branch solutions are characterised by a tall velocity streak with multiscale multiple vortical structures. At the higher end of R-S, an incipient multiscale structure is found. The LES turbulence occasionally visits vertically localised states whose vortical structure resembles the present vertically localised LES equilibria.

    DOI: 10.1017/jfm.2017.450

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  • Coherent structures in statistically stationary homogeneous shear turbulence Reviewed

    Siwei Dong, Adrian Lozano-Duran, Atsushi Sekimoto, Javier Jimenez

    JOURNAL OF FLUID MECHANICS   816   167 - 208   2017.4

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    The three-dimensional vortex clusters, and the structures based on the quadrant classification of the intense tangential Reynolds stress (Qs), are studied in direct numerical simulations of statistically stationary homogeneous shear turbulence (HST) at Taylor microscale Reynolds number Re-lambda approximate to 50-250, with emphasis on comparisons with turbulent channels (CHs). The Qs and vortex clusters in HST are found to be versions of the corresponding detached (in the sense of del Alamo et al. (J. Fluid Mech., vol. 561 (2006), pp. 329-358)) structures in CHs, although statistically symmetrised with respect to the substitution of sweeps by ejections and vice versa. In turn, these are more symmetric versions of the corresponding attached Qs and clusters. In both flows, only co-gradient sweeps and ejections larger than the local Corrsin scale are found to couple with the shear. They are oriented anisotropically, and are responsible for carrying most of the total Reynolds stress. Most large eddies in CHs are attached to the wall, but it is shown that this is probably a geometric consequence of their size, rather than the reason for their dynamical significance. Most small Q structures associated with different quadrants are far from each other in comparison to their size, but those that are close to each other tend to form quasi-streamwise trains of groups of a sweep and an ejection paired side by side in the spanwise direction, with a vortex cluster in between, generalising to three dimensions the corresponding arrangement of attached eddies in CHs. These pairs are organised around an inclined large-scale conditional vortex 'roller', and it is shown that the composite structure tends to be located at the interface between high-and low-velocity streaks, as well as in strong 'co-gradient' shear layers that separate streaks of either sign in which velocity is more uniform. It is further found that the conditional rollers are terminated by 'hooks' reminiscent of hairpins, both upright and inverted. The inverted hook weakens as the structures approach the wall, while the upright one changes little. At the same time, the inclination of the roller with respect to the mean velocity decreases from 45 degrees in HST to quasi-streamwise for wall-attached eddies. Many of these observations are generalised to intense Reynolds stresses formed with different pairs of velocity components, and it is shown that most properties of the small structures can be traced to their definitions, rather than to their dynamics. It is concluded that the larger Reynolds-stress structures are associated with shear turbulence, rather than with the presence of a wall, while the smaller ones are generic to turbulence in general, whether sheared or not.

    DOI: 10.1017/jfm.2017.78

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  • Coherent structures in a self-similar adverse pressure gradient turbulent boundary layer Reviewed

    A. Sekimoto, V. Kitsios, C. Atkinson, J. Jiménez, J. Soria

    Proceedings of 20th Australasian Fluid Mechanics Conference   2016.12

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  • Experimental measurements of a self-similar adverse pressure gradient turbulent boundary layer Reviewed

    C. Atkinson, A.-J. Buchner, A. Sekimoto, V. Kitsios, J. Soria

    Proceedings of 20th Australasian Fluid Mechanics Conference   2016.12

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  • Unstable periodic orbits in plane Couette flow with the Smagorinsky model Reviewed

    Eiichi Sasaki, Genta Kawahara, Atsushi Sekimoto, Javier Jemenez

    2ND MULTIFLOW SUMMER SCHOOL ON TURBULENCE   708 ( 1 )   2016.4

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    We aim at a description of the logarithmic velocity profile of wall turbulence in terms of unstable periodic orbits (UPOs) for plane Couette flow with a Smagorinsky-type eddy viscosity model. We study the bifurcation structure with respect to the Smagorinsky constant, arising from the gentle UPO reported by Kawahara and Kida [1] for the Navier-Stokes (NS) equation. We find that the obtained UPOs in the large eddy simulation (LES) system connect to those in the NS system, and that the gentle UPO in the LES system is an edge state branch whose stable manifold separates LES turbulence from an LES 'laminar' state. As the Reynolds number decreases this solution arises as the saddle solution of the saddle-node bifurcation. Meanwhile, the mean and root-mean-square velocity profiles of the node solution of the LES gentle UPO are in good agreement with those of LES turbulence.

    DOI: 10.1088/1742-6596/708/1/012003

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  • Direct numerical simulation of statistically stationary and homogeneous shear turbulence and its relation to other shear flows Reviewed

    Atsushi Sekimoto, Siwei Dong, Javier Jimenez

    PHYSICS OF FLUIDS   28 ( 3 )   2016.3

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    Statistically stationary and homogeneous shear turbulence (SS-HST) is investigated by means of a new direct numerical simulation code, spectral in the two horizontal directions and compact-finite-differences in the direction of the shear. No remeshing is used to impose the shear-periodic boundary condition. The influence of the geometry of the computational box is explored. Since HST has no characteristic outer length scale and tends to fill the computational domain, long-term simulations of HST are "minimal" in the sense of containing on average only a few large-scale structures. It is found that the main limit is the spanwise box width, L-z, which sets the length and velocity scales of the turbulence, and that the two other box dimensions should be sufficiently large (L-x greater than or similar to 2L(z), L-y greater than or similar to L-z) to prevent other directions to be constrained as well. It is also found that very long boxes, L-x greater than or similar to 2L(y), couple with the passing period of the shear-periodic boundary condition, and develop strong unphysical linearized bursts. Within those limits, the flow shows interesting similarities and differences with other shear flows, and in particular with the logarithmic layer of wall-bounded turbulence. They are explored in some detail. They include a self-sustaining process for large-scale streaks and quasi-periodic bursting. The bursting time scale is approximately universal, similar to 20S(-1), and the availability of two different bursting systems allows the growth of the bursts to be related with some confidence to the shearing of initially isotropic turbulence. It is concluded that SS-HST, conducted within the proper computational parameters, is a very promising system to study shear turbulence in general. (C) 2016 AIP Publishing LLC.

    DOI: 10.1063/1.4942496

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  • Turbulence- and buoyancy-driven secondary flow in a horizontal square duct heated from below Reviewed

    A. Sekimoto, G. Kawahara, K. Sekiyama, M. Uhlmann, A. Pinelli

    PHYSICS OF FLUIDS   23 ( 7 )   2011.7

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    Direct numerical simulations of fully developed turbulent flows in a horizontal square duct heated from below are performed at bulk Reynolds numbers Re(b) = 3000 and 4400 (based on duct width H) and bulk Richardson numbers 0 &lt;= Ri &lt;= 1.03. The primary objective of the numerical simulations concerns the characterization of the mean secondary flow that develops in this class of flows. On one hand, it is known that turbulent isothermal flow in a square duct presents secondary mean motions of Prandtl&apos;s second kind that finds its origin in the behavior of turbulence structures. On the other hand, thermal convection drives a mean secondary motion of Prandtl&apos;s first kind directly induced by buoyancy. As far as the mean structure of the cross-stream motion is concerned, it is found that different types of secondary flow regimes take place when increasing the value of the Richardson number. The mean secondary flow in the range 0.025 less than or similar to Ri less than or similar to 0.25 is characterized by a single large-scale thermal convection roll and four turbulence-driven corner vortices of the opposite sense of rotation to the roll, as contrasted with the classical scenario of the eight-vortex secondary flow pattern typical of isothermal turbulent square-duct flow. This remarkable structural difference in the corner regions can be interpreted in terms of combined effects, on instantaneous streamwise vortices, of the large-scale circulation and of the geometrical constraint by the duct corner. When further increasing the Richardson number, i.e., Ri greater than or similar to 0.25, the structure of the mean secondary flow is solely determined by the large-scale circulation induced by the buoyancy force. In this regime, the additional mean cross-stream motion is characterized by the presence of two distinct buoyancy-driven vortices of opposite sense of rotation to the circulation only in two of the four corner regions. With increasing Ri, the large-scale circulation is found to enhance the wall skin friction and heat transfer. In the significant-buoyancy regime Ri greater than or similar to 0.25, the mean cross-stream motion and its rms fluctuations are found to scale, respectively, with the buoyancy-induced velocity u(g)=root g beta Delta TH (g, beta, and Delta T being the gravity acceleration, the volumetric coefficient of thermal expansion, and the temperature difference across the duct, respectively) and with the mixed velocity scale root(nu/H)u(g) (nu being the kinematic viscosity). It is suggested that the probable scalings for the rms of streamwise velocity component and of temperature fluctuation are related with the friction velocity u(tau) and friction temperature T(tau) according to the magnitudes u(tau)(2)/ and T(tau)u(tau)/root(nu/H)u(g), respectively. (C) 2011 American Institute of Physics. [doi:10.1063/1.3593462]

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  • Reynolds number dependence of mean flow structure in square duct turbulence Reviewed

    Alfredo Pinelli, Markus Uhlmann, Atsushi Sekimoto, Genta Kawahara

    JOURNAL OF FLUID MECHANICS   644   107 - 122   2010.2

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    We have performed direct numerical Simulations of turbulent flows in a square duct considering a range of Reynolds numbers spanning from a marginal state up to fully developed turbulent states at low Reynolds numbers. The main motivation stems from the relatively poor knowledge about the basic physical mechanisms that are responsible for one of the most outstanding features of this class of turbulent flows: Prandtl&apos;s secondary motion of the second kind. In particular, the focus is upon the role of flow structures in its generation and characterization when increasing the Reynolds number. We present a two-fold scenario. On the one hand, buffer layer structures determine the distribution of mean streamwise vorticity. On the other hand, the shape and the quantitative character of the mean secondary flow, defined through the mean cross-stream function, are influenced by motions taking place at larger scales. It is shown that high velocity streaks are preferentially located in the corner region (e.g. less than 50 wall units apart from a sidewall), flanked by low velocity ones. These locations are determined by the positioning of quasi-streamwise vortices with a preferential sign of rotation in agreement with the above described velocity streaks&apos; positions. This preferential arrangement of the classical buffer layer structures determines the pattern of the mean streamwise vorticity that approaches the corners with increasing Reynolds number. On the other hand, the centre of the mean secondary flow, defined as the position of the extrema of the mean cross-stream function (Computed using the mean streamwise vorticity), remains at a constant location departing from the mean streamwise vorticity field for larger Reynolds numbers, i.e. it scales in outer units. This paper also presents a detailed validation of the numerical technique including a comparison of the numerical results with data obtained from a companion experiment.

    DOI: 10.1017/S0022112009992242

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  • The effect of coherent structures on the secondary flow in a square duct Reviewed

    A. Sekimoto, A. Pinelli, M. Uhlmann, G. Kawahara

    ADVANCES IN TURBULENCE XII - PROCEEDINGS OF THE 12TH EUROMECH EUROPEAN TURBULENCE CONFERENCE   132   329 - 332   2009.12

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    DOI: 10.1007/978-3-642-03085-7-80

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  • Buoyancy effects on low-Reynolds-number turbulent flow in a horizontal square-duct Reviewed

    Sekiyama Kazuhide, Sekimoto Atsushi, Wakabayashi Hiroki, Kawahara Genta, Uhlmann Markus, Pinelli Alfredo

    日本流体力学会年会講演論文集   2008   539 - 542   2009.4

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    DNS of fully developed turbulent flow in a horizontal square-duct heated from below is performed at Re=3000, 4400 and Ri=0-2.2 to examine buoyancy effects on structures and statistics of low-Reynolds-number duct turbulence. It is found that the effects of buoyancy appear at Ri&amp;ap;0.1, roughly independently of Re. At Ri&gt;0.1 cross-axial thermal convection, which is represented by single large-scale circulation, significantly affects the duct turbulence.

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  • Coherent structures in marginally turbulent square duct flow Reviewed

    Markus Uhlmann, Alfredo Pinelli, Atsushi Sekimoto, Genta Kawahara

    IUTAM SYMPOSIUM ON COMPUTATIONAL PHYSICS AND NEW PERSPECTIVES IN TURBULENCE   4   137 - 142   2008.12

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    Direct numerical simulation of fully developed turbulent flow in a straight square duct was performed in order to determine the minimal requirements for self-sustaining turbulence. It was found that turbulence can be maintained for values of the bulk Reynolds number above approximately 1100, corresponding to a friction-velocity-based Reynolds number of 80. The minimum value for the stream-wise period of the computational domain measures around 190 wall units, roughly independently of the Reynolds number. Furthermore, we present a characterization of the marginal state, where coherent structures are found to have significant relevance to the appearance of secondary flow of Prandtl's second kind.

    DOI: 10.1007/978-1-4020-6472-2_21

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  • Characterisation of marginally turbulent square duct flow Reviewed

    M. Uhlmann, A. Pinelli, A. Sekimoto, G. Kawahara

    ADVANCES IN TURBULENCE XI   117   41 - 43   2007.12

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  • 最近の化学工学72 化学工学系流体シミュレーションの最前線,基礎・実践・将来展望

    化学工学会, 粒子, 流体プロセス部会( Role: Contributor ,  第2章「乱流シミュレーション」)

    化学工学会関東支部編  2024.1 

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  • 臨界レイノルズ数付近における矩形ダクト乱流中の二次流れと熱的制御

    関本敦

    東京大学情報基盤センター・スーパーコンピューティングニュース特集号   25 ( 特集号 )   20 - 25   2023.8

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  • Couette-Poiseuille流れにおける大規模構造の解析

    関本 敦

    東京大学情報基盤センター・スーパーコンピューティングニュース   24 ( 5 )   23 - 30   2022.9

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  • ミニマルスパン・チャンネル乱流の直接数値計算による乱流伝熱解析

    関本 敦

    東京大学情報基盤センター・スーパーコンピューティングニュース   24 ( 4 )   37 - 39   2022.7

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  • 正方形ダクト乱流の直接数値計算の GPU 加速 Invited

    関本 敦

    東京大学情報基盤センター・スーパーコンピューティングニュース 特集号:2020年度「若手・女性利用者推薦」前期・後期課題 成果報告   23   57 - 64   2021.8

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  • 化学工学年鑑2020, 4.3 対流伝熱促進・制御

    関本 敦

    化学工学   84 ( 10 )   2020

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  • Coherent structures and invariant solutions in a statistically stationary homogeneous shear turbulence Invited

    Atsushi Sekimoto

    39 ( 3 )   126 - 129   2020

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  • 統計的に定常な一様剪断乱流への安定密度成層の影響

    関本 敦

    東京大学情報基盤センター・スーパーコンピューティングニュース 特集:平成30年度「若手・女性利用者推薦」前期・後期課題 成果報告   21 ( 1 )   96 - 98   2019.8

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    特集:平成30年度「若手・女性利用者推薦」前期・後期課題 成果報告

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  • 化学工学年鑑2019, 4.3 対流伝熱促進・制御

    化学工学   83 ( 10 )   583 - 584   2019.3

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  • Numerical investigation of crystal growth of InGaSb on board the ISS

    沖田和也, XIN Jin, 関本敦, 岡野泰則, 稲富裕光, 早川泰弘

    結晶成長国内会議予稿集(CD-ROM)   48th   2019

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  • 数値解析を用いた国際宇宙ステーション内InGaSb結晶成長条件の設定と拡散係数の算出

    岡野泰則, XIN Jin, 山本卓也, 関本敦, 早川泰弘, 稲富裕光

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   66th   2019

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  • Direct numerical simulation of self-similar adverse-pressure-gradient turbulent boundary layer and scaling for turbulent statistics Invited

    Atsushi SEKIMOTO, Vassili Kitsios, Callum Atkinson, Julio Soria

    37 ( 6 )   536 - 539   2018.12

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  • Vertically localized equilibrium in the large eddy simulation of homogeneous shear turbulence(<Special Review>Selected Researches in Annual Meeting 2015) Invited

    Atsushi SEKIMOTO, Javier JIMENEZ, School of Aeronautics Technical, University Madrid

    ながれ : 日本流体力学会誌 = Journal of Japan Society of Fluid Mechanics   34 ( 6 )   413 - 417   2015.12

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  • 一様剪断流における不安定周期解 Invited

    関本 敦, S. Dong, J. Jiménez

    京都大学数理解析研究所共同研究集会 ― 大スケール流体運動と乱流揺らぎ,考究録   1943   34 - 46   2015.4

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  • The Post-doc Life in the Technical University in Madrid, Spain

    関本 敦

    混相流   27 ( 4 )   460 - 463   2013.12

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  • Turbulence- and buoyancy-driven secondary flow in a horizontal square duct heated from below

    A. Sekimoto, G. Kawahara, K. Sekiyama, M. Uhlmann, A. Pinelli

    PHYSICS OF FLUIDS   23 ( 7 )   2011.7

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    Direct numerical simulations of fully developed turbulent flows in a horizontal square duct heated from below are performed at bulk Reynolds numbers Re(b) = 3000 and 4400 (based on duct width H) and bulk Richardson numbers 0 &lt;= Ri &lt;= 1.03. The primary objective of the numerical simulations concerns the characterization of the mean secondary flow that develops in this class of flows. On one hand, it is known that turbulent isothermal flow in a square duct presents secondary mean motions of Prandtl&apos;s second kind that finds its origin in the behavior of turbulence structures. On the other hand, thermal convection drives a mean secondary motion of Prandtl&apos;s first kind directly induced by buoyancy. As far as the mean structure of the cross-stream motion is concerned, it is found that different types of secondary flow regimes take place when increasing the value of the Richardson number. The mean secondary flow in the range 0.025 less than or similar to Ri less than or similar to 0.25 is characterized by a single large-scale thermal convection roll and four turbulence-driven corner vortices of the opposite sense of rotation to the roll, as contrasted with the classical scenario of the eight-vortex secondary flow pattern typical of isothermal turbulent square-duct flow. This remarkable structural difference in the corner regions can be interpreted in terms of combined effects, on instantaneous streamwise vortices, of the large-scale circulation and of the geometrical constraint by the duct corner. When further increasing the Richardson number, i.e., Ri greater than or similar to 0.25, the structure of the mean secondary flow is solely determined by the large-scale circulation induced by the buoyancy force. In this regime, the additional mean cross-stream motion is characterized by the presence of two distinct buoyancy-driven vortices of opposite sense of rotation to the circulation only in two of the four corner regions. With increasing Ri, the large-scale circulation is found to enhance the wall skin friction and heat transfer. In the significant-buoyancy regime Ri greater than or similar to 0.25, the mean cross-stream motion and its rms fluctuations are found to scale, respectively, with the buoyancy-induced velocity u(g)=root g beta Delta TH (g, beta, and Delta T being the gravity acceleration, the volumetric coefficient of thermal expansion, and the temperature difference across the duct, respectively) and with the mixed velocity scale root(nu/H)u(g) (nu being the kinematic viscosity). It is suggested that the probable scalings for the rms of streamwise velocity component and of temperature fluctuation are related with the friction velocity u(tau) and friction temperature T(tau) according to the magnitudes u(tau)(2)/ and T(tau)u(tau)/root(nu/H)u(g), respectively. (C) 2011 American Institute of Physics. [doi:10.1063/1.3593462]

    DOI: 10.1063/1.3593462

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  • 302 Spatially localized turbulence structures in a rectangular duct

    WAKABAYASHI Hiroki, SEKIMOTO Atsushi, SHIMIZU Masaki, UHLMANN Markus, KAWAHARA Genta

    関西支部講演会講演論文集   2011 ( 86 )   3 - 2"   2011.3

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  • 「逆解析」機能搭載 三次元気流解析ソフト FlowDesignerによる最適設計

    関本敦, 池島薫, 桃瀬一成

    クリーンテクノロジー   20 ( 12 )   70 - 74   2010.12

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  • 水平正方形ダクトにおける乱流・浮力駆動二次流れ (乱流の動力学的記述と統計力学的記述の相補性)

    関山 和英, 関本 敦, 河原 源太, ウルマン マルクス, ピネリ アルフレド

    数理解析研究所講究録   1721   124 - 134   2010.12

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  • 「逆解析」機能搭載 三次元気流解析ソフト FlowDesignerによる最適設計

    関本敦, 池島薫, 桃瀬一成

    クリーンテクノロジー   20 ( 10 )   74 - 78   2010.10

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  • 水平正方形ダクトにおける乱流・浮力駆動二次流れ

    河原源太, 関本敦, UHLMANN Markus, PINNELLI Alfredo

    日本機械学会年次大会講演論文集   2010 ( Vol.2 )   31 - 32   2010.9

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    Direct numerical simulations of fully developed turbulent flows in a horizontal square duct heated from below are performed at bulk Reynolds numbers Re_b = 3000, 4400 in the range of bulk Richardson numbers 0 &amp;le; Ri &amp;le; 1.03 to characterize turbulence- and buoyancy-driven mean secondary flow. It is observed that for 0.025 &amp;lsim; Ri &amp;lsim; 0.25 turbulence-driven secondary flow of a usual eight-vortex pattern is deformed by the effect of buoyancy into turbulence- and buoyancy-driven flow represented by single large-scale circulation and four corner vortices of opposite sense of rotation to the circulation. This remarkable structural difference in the corner regions can be interpreted in terms of combined effects, on instantaneous streamwise vortices, of the large-scale circulation and of the geometrical constraint by impermeable duct walls.

    DOI: 10.1299/jsmemecjo.2010.2.0_31

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  • 矩形ダクト流における乱流パフと乱流斑点―ダクト断面縦横比の影響―

    若林弘輝, 関本敦, 河原源太, UHLMANN M, PINELLI A

    理論応用力学講演会講演論文集   59th   211 - 212   2010.6

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  • Erratum: Reynolds number dependence of mean flow structure in square duct turbulence (Journal of Fluid Mechanics 644 (107-122) doi:10.1017/ S0022112009992242) Reviewed

    Pinelli A, Uhlmann M, Sekimoto A, Kawahara G

    Journal of Fluid Mechanics   653   2010.6

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    DOI: 10.1017/S0022112010001849

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  • 正方形ダクト乱流中の秩序構造と二次流れ (乱流の多重性・階層性とその数理的構造)

    関本 敦, 河原 源太, Uhlmann Markus, Pinelli Alfredo

    数理解析研究所講究録   1673   93 - 103   2010.1

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  • Turbulent puff and spot in rectangular-duct flow:The effect of an aspect ratio of a duct

    Wakabayashi Hiroki, Sekimoto Atsushi, Kawahara Genta, Uhlmann Markus, Pinelli Alfredo

    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan   59 ( 0 )   108 - 108   2010

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    Direct numerical simulation of rectangular-duct flow is performed to investigate the properties of turbulent puff and spot appearing at low Reynolds numbers. Structures observed are very different depending on the aspect ratio of a duct. In the case of the aspect ratio close to unity, it is confirmed that a turbulent puff appears to be similar to that observed in pipe flow and square-duct flow. In the case of the aspect ratio far from unity, on the other hand, turbulence is localized not only in the streamwise direction but also in the spanwise direction, and it is similar to a so-called turbulent spot.

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  • 0209 Puff structure in square-duct flow

    SEKIMOTO Atsushi, KAWAHARA Genta, UHLMANN Markus, PINELLI Alfredo

    Fluids engineering conference ...   2009   111 - 112   2009.11

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    We present the results obtained from direct numerical simulations of square-duct flow in a long streamwise computational domain at a range of Reynolds numbers 750&amp;le;Re_b&amp;le;1500, Re_b being based on mean bulk velocity and duct half width. Localized turbulence travelling downstream, equiliblium &#039;puff&#039;, is identified at the Reynolds number Re_b=850-1050. The mean secondary flow in &#039;puff&#039; region is found to exhibit eight-vortex patterns observed in the secondary motion of Prandtl&#039;s second kind in turbulent square duct flow.

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  • (行事報告) 流体若手夏の学校2009 –工学における流体シミュレーション技術– の報告

    関本 敦

    ながれ   28   433   2009.10

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  • Secondary flow and turbulence structures in a horizontal square-duct heated from below at low Reynolds numbers

    Sekimoto Atsushi, Sekiyama Kazuhide, Kawahara Genta, Uhlmann Markus, Pinelli Alfredo

    日本流体力学会年会講演論文集   2009   32 - 32   2009

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    Direct numerical simulations of fully developed low-Reynolds-number turbulent flow in a horizontal square duct heated from below are performed at Richardson numbers 0&amp;le;Ri&amp;le;1.03 to investigate the buoyancy effects on the coherent structures near the walls, i.e. streamwise vortices and associated streaks, and on turbulence-driven secondary flow of Prandtl&#039;s second kind. It is found that cross-streamwise thermal convection which is represented by single large-scale circulation appears to affect the coherent structures and the mean secondary flow for Ri&amp;gsim;0.025. As Ri is increased, the near-wall coherent structures are observed to appear more frequently in the region near one of the two corners on the wall, since they are swept along the wall towards the corner by the large-scale convection. The localization of the near-wall structures affects the profile of skin friction and heat transfer rate on the wall.

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  • Puff structure in square-duct flow

    関本敦, 河原源太, UHLMANN Markus, PINELLI Alfredo

    日本機械学会流体工学部門講演会講演論文集(CD-ROM)   87th   ROMBUNNO.0209   2009

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  • 正方形ダクト乱流の直接数値シミュレーション

    関本 敦, 河原源太, Uhlmann, M, Pinelli, A

    九州大学情報基盤研究開発センター広報   2 ( 2 )   43 - 49   2008.11

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    DOI: 10.15017/1470164

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  • 正方形ダクト乱流の直接数値シミュレーション

    関本 敦, 河原源太, Uhlmann, M, Pinelli, A

    東京大学情報基盤センター スーパーコンピューティングニュース   10 ( 5 )   2008.9

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  • 514 Turbulence Structures and Secondary Flow in a Square Duct

    KAWAHARA Genta, SEKIMOTO Atsushi, UHLMANN Markus, PINELLI Alfredo

    関西支部講演会講演論文集   2008 ( 83 )   "5 - 21"   2008.3

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  • 正方形ダクト流の乱流構造と二次流れ

    河原源太, 関本敦, UHLMANN Markus, PINELLI Alfredo

    日本機械学会関西支部定時総会講演会講演論文集   83rd   5.21   2008.3

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  • 203 Vortical structures in low-Reynolds-number turbulent square duct flow(2)

    SEKIMOTO Atsushi, KAWAHARA Genta, UHLMANN Markus, PINELLI Alfredo

    Fluids engineering conference ...   2007   "203 - 1"-"203-4"   2007.11

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    Spectral direct numerical simulations of fully developed turbulent flow in a straight square duct were performed in order to investigate flow structures at low Reynolds numbers. It was found that turbulence can be maintained for values of the bulk Reynolds number above approximately 1100, and the minimum value for the streamwise period of the computational domain is around 190 wall units, which is roughly independent of the Reynolds number. The flow state at marginal Reynolds numbers exhibits a 4-vortex secondary flow structure alternating in time, whereas the fully turbulent one presents the usual 8-vortex pattern. It is shown that buffer layer coherent structures play a crucial role in the appearance of secondary flow of Prandtl&#039;s second kind at the marginal Reynolds numbers. The coherent structures are observed to affect the mean primary and secondary flow even at higher Reynolds numbers.

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  • 905 Coherent Structures of marginally turbulent square duct flow

    SEKIMOTO Atsushi, KAWAHARA Genta, UHLMANN Marukus, PINELLI Alfred

    関西支部講演会講演論文集   2007 ( 82 )   "9 - 5"   2007.3

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  • 低レイノルズ数における正方形管路内乱流の秩序構造

    関本敦, 河原源太, UHLMANN Marukus, PINELLI Alfred

    日本機械学会関西支部定時総会講演会講演論文集   82nd ( 82 )   9.5 - 5"   2007.3

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  • 低レイノルズ数正方形ダクト乱流における秩序状態

    関本敦, 河原源太, UHLMANN Markus, PINELLI Alfred

    理論応用力学講演会講演論文集   56th   109 - 110   2007.3

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  • Coherent states in marginally turbulent square duct flow

    Sekimoto Atsushi, Kawahara Genta, Uhlmann Markus, Pinelli Alfredo

    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan   56 ( 0 )   46 - 46   2007

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    We have performed direct numerical simulation of fully developed turbulent flow in a straight duct with square cross-section. The main objective of the present study is to determine the minimal requirements for maintaining turbulence in duct flows. A detailed analysis of this limit regime allows to elucidate the dominant mechanisms that govern such a marginally turbulent state: It is shown that in this state, on the verge of laminarization, the self-sustaining coherent structures, i.e. streamwise vortices and streaks, have a cross-streamwise length scale comparable with the duct width, so that the coherent structures have significant relevance to the appearance of secondary flow of the Prandtl&#039;s second kind.

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  • Vortical structures in low-Reynolds-number turbulent square duct flow

    関本敦, 河原源太, UHLMANN Markus, PINELLI Alfredo

    日本機械学会流体工学部門講演会講演論文集(CD-ROM)   85th   ROMBUNNO.203   2007

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Presentations

  • Invariant solutions in DNS/LES of statistically stationary homogeneous shear flow Invited

    Atsushi Sekimoto

    Scientific Computing Across Scales: Extreme Events and Criticality in Fluid Mechanics  2019.4.18 

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    Event date: 2019.4.15 - 2019.4.19

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  • Buoyancy effect on the secondary flow and heat transfer in a marginally turbulent square duct Invited

    Atsushi SEKIMOTO, Mizuki NAKAMORI, Yasunori OKANO

    18th Asian Pacific Confederation of Chemical Engineering Congress (APCChE2019)  2019.9.26 

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  • Unstable periodic orbits in homogeneous shear flow, Monash Fluid Seminar Series Invited

    Atsushi Sekimoto

    Monash Fluid Seminar Series  2018.9.26 

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  • Self-Sustaining motions and periodic orbits in a statistically-stationary homogeneous shear flow Invited

    Atsushi Sekimoto

    RIMS camp-style seminar  2016.8.31 

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  • Direct numerical simulations of statistically-stationary homogeneous shear turbulence Invited

    Atsushi Sekimoto

    Seminar in the University of Melbourne  2016.8.5 

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  • 一様剪断流における不安定周期解 Invited

    関本 敦

    京都大学 数理解析研究所共同研究集会  2014.1.10 

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  • Inclined-vortex solutions in homogeneous shear flow Invited International conference

    Atsushi Sekimoto

    IUTAM Symposium on Vortex Dynamics: Formation, Structure and Function  2013.3.10 

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  • Thermal control of the streamwise vortices in a turbulent square-duct flow by a reinforcement learning

    Takashi Mitani, Atsushi Sekimoto

    the 6th R-CCS International Symposium  2024.1.29 

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    Event date: 2024.1.29 - 2024.1.30

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  • 数値流体シミュレーションにおけるデータ駆動型の能動パラメター制御

    関本 敦, 三谷 崇志, 伊賀 成啓

    第37回数値流体力学シンポジウム  2023.12.16 

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    Event date: 2023.12.15 - 2023.12.17

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  • 分散型強化学習による正方形ダクト乱流中の縦渦の熱的制御

    三谷 崇志, 関本 敦

    日本流体力学会 中四国九州支部 第32回支部講演会(岡山大学津島キャンパス)  2023.11.25 

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    Event date: 2023.11.25 - 2023.11.26

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  • 正方形ダクト中のプラントルの第二種二次流れの強化学習による加熱制御

    三谷 崇志, 関本 敦

    流体力学会年会2023  2023.9.21 

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    Event date: 2023.9.20 - 2023.9.22

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  • 三次元点群データを用いたモモの着果位置と果実品質の関係の3Dモデル構築

    河井 崇, 小坂勇貴, 林 優月, 安部雅治, 山本道輔, 関本 敦, 浜田和俊, 福田文夫, 高田大輔

    園芸学会令和5年度春季大会 

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    Event date: 2023.3.15 - 2023.3.22

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  • Scaling of Turbulence Statistics in Adverse-Pressure-Gradient Turbulent Boundary Layer Flow

    Atsushi Sekimoto, Vassili Kitsios, Callum Atkinson, Julio Soria

    Eighteenth International Conference on Flow Dynamics  2021.10.29 

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    Event date: 2021.10.27 - 2021.10.29

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  • 畜産業と住環境の調和を目指した郊外の臭気拡散解析

    幡山 純, 関本 敦

    日本機械学会2023年度年次大会  2023.9.5 

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  • データ駆動型の熱制御による流動設計 Invited

    関本敦

    IMI研究集会「流体数理・データ科学による乱流場の計測・予測・制御・設計」  2023.7.3 

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  • 地方都市での微気象予測による地域社会課題解決 Invited

    関本敦

    岡山大学AI・数理データサイエンスセンターサイバーフィジカル情報応用研究推進部門(Cypher)研究会  2023.6 

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  • 壁面加熱による低レイノルズ数正方形ダクト乱流の4つ渦平均二次流れの安定化

    三谷崇志, 関本敦

    流体力学会年会2022  2022.9.29 

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  • 統計的に定常な一様せん断乱流への浮力の影響

    関本敦, 後藤涼花

    流体力学会年会2022  2022.9.28 

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  • 研究紹介 Invited

    関本敦

    岡山大学 Cypher 7月研究会  2022.7 

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  • 臨界レイノルズ数付近における正方形ダクト内平均二次流れの熱的制御

    三谷 崇志, 関本 敦

    日本機械学会 中国四国学生会 第52回学生員卒業研究発表講演会  2022.3.3 

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  • 剥離寸前の逆圧力勾配境界層乱流の大規模数値計算と統計量のスケーリング則 Invited

    関本 敦

    MMDS 研究 集会「工学と数学の接点を求めて」 ,大阪大学(豊中キャンパス)  2019.11.14 

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  • 海外ポスドク生活と成長の軌跡 Invited

    関本 敦

    2019 年度日本機械学会年次大会・特別企画プログラム・ 大学教員人材の採用・育成を考える (秋田大学)  2019.9.10 

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  • 基礎セミナー:流体現象を解きほぐす数理科学「乱流の直接数値シミュレーション」 Invited

    関本 敦

    基礎セミナー:流体現象を解きほぐす数理科学  2018.6.22 

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  • 一様剪断流の LES における非線形サドル解 Invited

    関本 敦

    ダイナミクス研究会中野,明治大学  2018.6.14 

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  • 一様せん断流における不安定周期解 Invited

    関本 敦

    CMRU 数学連携セミナー, 明治大学  2016.8.25 

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  • 大規模並列直接数値計算の基礎と応用 Invited

    関本 敦

    研究集会「低侵襲性人工血管の開発とそれに伴う数 値解析手法の構築」九州大学マス・フォア・インダストリ研究所  2014.1.24 

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  • 一様せん断乱流の数値シミュレーション~不安定周期解による乱流の動力学の解明~ Invited

    関本 敦

    第 24 回 SMART セミナー,東北大学理学研究科  2014.1.17 

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Awards

  • 工学部 教育貢献賞

    2023.3   岡山大学  

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  • 工学部 ベストティーチャー賞

    2022.3   岡山大学  

    関本 敦

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  • 第52回 学生員卒業研究発表講演会 優秀発表賞

    2022.3   日本機械学会中国四国支部   臨界レイノルズ数付近における正方形ダクト内平均二次流れの熱的制御

    三谷 崇志

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  • 日本流体力学会「竜門賞」

    2020.4   日本流体力学会  

    関本 敦

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    Country:Japan

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  • 第 82 期定時総会講演会 フェロー賞

    2007.3   日本機械学会関西支部  

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Research Projects

  • 数理最適化理論に基づくデータ駆動型の先端流動制御

    2023.04

    稲盛財団  稲盛研究助成 

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  • 矩形ダクト流路内の粒子挙動の制御

    Grant number:HPTF21112  2022.04 - 2023.03

    (公財)ホソカワ粉体工学振興財団  (公財)ホソカワ粉体工学振興財団 研究助成 

    関本 敦

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  • 臨界レイノルズ数付近における矩形ダクト乱流中の二次流れと熱的制御

    2022.04 - 2023.03

    東京大学情報基盤センター  「若手・女性利用者推薦」 2022年度(前期) 

    関本 敦

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  • 矩形ダクト流路内の粒子挙動制御

    Grant number:HPTF21112  2022.04 - 2023.03

    (公財)ホソカワ粉体工学振興財団  (公財)ホソカワ粉体工学振興財団 研究助成 

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\800000

  • 共同研究

    2022.04 - 2022.07

    ナカシマプロペラ株式会社 

    関本 敦

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  • 逆圧力勾配下における乱流境界層の統計量スケーリング則と新たなLES基盤の創出

    Grant number:21K03876  2021.04 - 2024.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    関本 敦

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    Grant amount:\4290000 ( Direct expense: \3300000 、 Indirect expense:\990000 )

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  • GPU加速DNSコードを用いた正方形ダクト乱流の直接数値計算

    2020.04 - 2021.03

    東京大学情報基盤センター  若手・女性利用者推薦 

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  • Couette-Poiseuille 流れにおける大規模構造の解析

    2020.04 - 2021.03

    東京大学情報基盤センター  若手・女性利用者推薦 

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  • ミニマルスパン・チャネル乱流の直接数値計算による乱流伝熱解析

    2019.04 - 2020.03

    東京大学情報基盤センター  若手・女性利用者推薦課題 

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  • 世界最高レイノルズ数乱流データベース構築のためのGPU-DNSコードの作成

    2019.04 - 2020.03

    東京大学情報基盤センター  若手・女性利用者推薦課題 

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  • 安定密度成層下での一様せん断乱流の長時間統計と壁乱流との比較

    2018.10 - 2019.03

    東京大学情報基盤センター  若手利用者推薦課題(JHPCN萌芽型共同研究課題) 

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  • 逆圧力勾配境界層乱流の研究

    2018.09 - 2018.10

    (公財)航空機国際共同開発促進基金  国際交流助成 

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    Authorship:Principal investigator 

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  • Development of high-fidelity turbulence model based on invariant solutions

    Grant number:18K13689  2018.04 - 2020.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists  Grant-in-Aid for Early-Career Scientists

    Atsushi Sekimoto

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    Grant amount:\4160000 ( Direct expense: \3200000 、 Indirect expense:\960000 )

    The invariant solutions in the large-eddy simulation (LES), i.e., filtered Navier-Stokes equation, are investigated for the development of a high-fidelity turbulence model. The invariant solutions in uniform shear flow are traced along with the parameters, and new periodic orbits are obtained. These invariant solutions give us the theoretical background for the self-sustaining turbulence with eddy viscosity and the similarity with the self-sustaining motions of wall-bounded shear turbulence in the Navier-Stokes (NS) equation. The relatively high-Reynolds-number equilibrium in a plane Couette flow in NS equation is obtained, and the wall-bounded solutions resemble invariant solutions in the LES equation, which paves a way of developing a wall model for eddy viscosity.

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  • 不変解を用いたラージエディシミュレーションの高精度化

    2018.01 - 2019.03

    九州大学情報基盤研究開発センター  プロダクトラン課題 

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  • 正方形ダクト乱流の高精度直接数値計算コードのGPU加速

    2018.01 - 2019.03

    九州大学情報基盤研究開発センター  ベンチマーク課題 

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    Authorship:Principal investigator 

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  • Minimal plane Couette flow with pressure gradients

    2017.06

    European Research Council  European Research Council, the Third Madrid Turbulence Workshop  共同研究

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    Authorship:Principal investigator 

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  • The secondary flow and large-scale structures in turbulent square duct flow at high Reynolds numbers

    Grant number:09J00546  2009

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows  Grant-in-Aid for JSPS Fellows

    関本 敦

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    Grant amount:\1200000 ( Direct expense: \1200000 )

    正方形ダクト流れの平均流にはプラントルの第二種二次流れと呼ばれる角へと向かう流れが存在する.本研究ではスペクトル法を用いた乱流の直接シミュレーションによって,二次流れの生成メカニズムを乱流中の秩序構造の観点から解明することを目的とし,以下の二つのアプローチをとった.
    1.高レイノルズ数領域における二次流れの生成機構の解明,および二次流れのスケーリング.
    高レイノルズ数領域では,流路幅全体に渡る大規模な乱流構造が存在することが知られており,この構造に着目して二次流れの生成機構の解明を試みた.また,すでに得られている低レイノルズ数の結果と,今回実施した高レイノルズ数領域のDNSの結果から二次流れのスケーリング則を明らかにした.正方形ダクト乱流では側壁の影響により,特徴的な壁面剪断応力分布や平均二次流れがみられる.これらの要因を乱流中の秩序構造の観点から深く調査した例はこれまでにない.
    2.非圧縮ナビエ・ストークス(NS)方程式の不安定周期解に基づき二次流れの生成機構を理論的に解明する.
    非圧縮NS方程式の不安定な平衡解(定常進行波解)や周期解を数値的に求めることにより,秩序構造と二次流れの関係の理論的な理解を深めることができる.今回,秩序構造の特徴を有し,かつ,二次流れをよく表す定常進行波解を数値的に求めた.二次流れの生成機構の理論的解明の新たな糸口とすることができるとともに,乱流遷移問題に関しても新たな知見が得られたことになる.

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Class subject in charge

  • Data-Driven Numerical Analysis (2023academic year) Late  - 月5~6

  • Advanced Data-Inspired Science (2023academic year) Late  - その他

  • Data Driven Computation - Basics (2023academic year) Second semester  - 火3~4,金3~4

  • Data Driven Computation - Application (2023academic year) Fourth semester  - 火7~8,金7~8

  • Advanced Data-driven Computational Methods (2023academic year) Late  - その他

  • Technical English (2023academic year) 3rd and 4th semester  - [第3学期]水3~4, [第4学期]水1~2

  • Differential Equation (2023academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation (2023academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation 1 (2023academic year) Third semester  - 火3~4

  • Differential Equation 2 (2023academic year) Fourth semester  - 火3~4

  • Advanced Mathematical Science in Liberal Arts (2023academic year) Third semester  - 水3~4

  • Numerical Computations (2023academic year) Third semester  - 月3~4,木1~2

  • Special Research (2023academic year) Year-round  - その他

  • Advanced Study (2023academic year) Other  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2023academic year) Prophase  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2023academic year) Late  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2023academic year) Late  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2023academic year) Prophase  - その他

  • Seminar in Numerical Analysis of Flow Phenomina A (2023academic year) Year-round  - その他

  • Seminar in Numerical Analysis of Flow Phenomina A (2023academic year) Year-round  - その他

  • Seminar in Numerical Analysis of Flow Phenomina B (2023academic year) Year-round  - その他

  • Seminar in Numerical Analysis of Flow Phenomina B (2023academic year) Year-round  - その他

  • Advanced Seminar in Numerical Analysis of Flow Phenomena (2023academic year) Year-round  - その他

  • Environmental and Informational Modeling 1 (2023academic year) Second semester  - 火3,金3

  • Environmental and Informational Modeling 2 (2023academic year) Second semester  - 火4,金4

  • Computational Analysis 1 (2023academic year) Third semester  - 月3,木1

  • Computational Analysis 2 (2023academic year) Third semester  - 月4,木2

  • Inverse Analysis and Data Assimilation (2023academic year) Late  - 月5~6

  • Advanced Data-Inspired Science (2022academic year) Late  - その他

  • Differential Equation (2022academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation (2022academic year) 3rd and 4th semester  - 火3~4

  • Differential Equation 1 (2022academic year) Third semester  - 火3~4

  • Differential Equation 2 (2022academic year) Fourth semester  - 火3~4

  • Advanced Mathematical Science in Liberal Arts (2022academic year) Third semester  - 月5~6

  • Numerical Computations (2022academic year) Third semester  - 月3~4,木1~2

  • Special Research (2022academic year) Year-round  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2022academic year) Prophase  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2022academic year) Late  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2022academic year) Prophase  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2022academic year) Late  - その他

  • Environmental and Informational Modeling 1 (2022academic year) Third semester  - 金5~6

  • Environmental and Informational Modeling 2 (2022academic year) Fourth semester  - 金5~6

  • Computational Analysis 1 (2022academic year) Third semester  - 月3,木1

  • Computational Analysis 2 (2022academic year) Third semester  - 月4,木2

  • Numerical Simulation of Nonlinear Phenomena (2022academic year) Prophase  - 月5~6

  • Data-Driven Numerical Analysis (2021academic year) Prophase  - 月3~4

  • Advanced Data-Inspired Science (2021academic year) Late  - その他

  • Differential Equation (2021academic year) 3rd and 4th semester  - 火3,火4

  • Differential Equation (2021academic year) 3rd and 4th semester  - [第3学期]火3,火4, [第4学期]火3~4

  • Differential Equation (2021academic year) 3rd and 4th semester  - [第3学期]火3,火4, [第4学期]火3~4

  • Differential Equation 1 (2021academic year) Third semester  - 火3,火4

  • Differential Equation 2 (2021academic year) Fourth semester  - 火3,火4

  • Advanced Mathematical Science in Liberal Arts (2021academic year) Third semester  - 月5~6

  • Special Research (2021academic year) Year-round  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2021academic year) Prophase  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2021academic year) Late  - その他

  • Seminar on Numerical Analysis of Flow Phenomena (2021academic year) Late  - その他

  • Seminar in Numerical Analysis of Flow Phenomena (2021academic year) Prophase  - その他

  • Environmental and Informational Modeling (2021academic year) 3rd and 4th semester  - 金5~6

  • Environmental and Informational Modeling 1 (2021academic year) Third semester  - 金5~6

  • Environmental and Informational Modeling 2 (2021academic year) Fourth semester  - 金5~6

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Social Activities

  • 基礎セミナー「基礎セミナー:流体現象を解きほぐす数理科学」(高大連携講座)

    Role(s):Lecturer

    2018.6.22

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    Type:Seminar, workshop

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  • 大阪大学SEEDS実感科学研究プログラム

    Role(s):Advisor, Organizing member

    大阪大学 SEEDSプログラム  2018.4.1 - 2019.3.31

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Media Coverage

  • Better understanding of Marangoni flows may help improve floating-zone crystal growth

    AIP Scilight  2020.3

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    https://doi.org/10.1063/10.0000898

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Academic Activities

  • 日本流体力学会 第32回中四国・九州支部講演会

    Role(s):Planning, management, etc., Panel moderator, session chair, etc.

    日本流体力学会  2023.11.25 - 2023.11.26

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  • 日本流体力学会年会2023 セッションオーガナイザ

    Role(s):Planning, management, etc.

    日本流体力学会  2023.9.20 - 2023.9.22

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  • 九州大学IMI研究集会「流体数理・データ科学による乱流場の計測・予測・制御・設計」組織委員

    Role(s):Planning, management, etc., Panel moderator, session chair, etc.

    九州大学応用力学研究所  2023.7.3 - 2023.7.6

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  • 日本流体力学会年会2022 セッションオーガナイザー

    Role(s):Panel moderator, session chair, etc.

    日本流体力学会  2022.9.27 - 2022.9.29

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    Type:Academic society, research group, etc. 

  • 日本流体力学会年会2022 セッションオーガナイザ

    Role(s):Planning, management, etc., Panel moderator, session chair, etc.

    日本流体力学会  2022.9.27 - 2022.9.29

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  • 第33回CES21オンライン講演会

    Role(s):Planning, management, etc.

    化学工学会関西支部若手の会「CES21」  2021.1.29

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  • 京都大学数理解析研究所(RIMS)合宿型セミナー「壁面せん断流のダイナミクス」の企画,開催

    Role(s):Planning, management, etc.

    2016.8.31 - 2016.9.2

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  • The 2nd European Research Council, MultiFlow project, Summer Workshop

    Role(s):Planning, management, etc.

    2015.5.25 - 2015.6.26

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    Type:Competition, symposium, etc. 

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  • The 1st European Research Council, MultiFlow project, Summer Workshop

    Role(s):Planning, management, etc.

    2013.6.10 - 2013.7.12

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    Type:Competition, symposium, etc. 

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  • 流体若手夏の学校・幹事

    Role(s):Planning, management, etc.

    2009.8.1 - 2009.8.3

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    Type:Academic society, research group, etc. 

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