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Affiliation |
Engineering educational research section Mechanical Intelligence Engineering Program |
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Title |
Associate Professor |
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External Link |
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MIYAUCHI Suguru
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Papers 【 display / non-display 】
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Miyauchi S., Hosoi K., Tsuda S., Hayase T., Funamoto K.
AIP Advances 13 ( 4 ) 2023.3
Authorship：Lead author, Corresponding author Publishing type：Research paper (scientific journal) Publisher：AIP Advances
It is generally believed that thrombus formation does not occur in the left ventricle (LV) because of the high speed of blood flow. However, the LV has complex internal structures such as trabeculae carneae (TC) and papillary muscles (PM) on its inner wall, which may cause blood stagnation resulting in thrombus formation. In this study, the effects of the TC, PM, and torsional motion on the hemodynamics in the LV were investigated by computational fluid dynamics (CFD) analyses. An LV model was reconstructed from magnetic resonance imaging, and the shape was modified to mimic TC and PM. Then, the CFD analyses of blood flow were performed using several different combinations of TC, PM, and torsional motion. As the results, the presence of TC decreased the time-averaged wall shear stress and increased the relative residence time (RRT) of a blood stagnation index at the apex of the LV model. The TC-induced blood stagnation was also confirmed by a transportation analysis of the passive scalar. These hemodynamic changes were attributed to the fact that TC blocked the large vortex structures generated during the diastole, thus preventing them from reaching the apex. Moreover, the PM only affected the hemodynamics in its immediate vicinity, and torsional motion caused irregular changes to the RRT level and distribution at the apex. Therefore, the complex internal structures and torsional motion of the LV could cause blood stagnation.
DOI： 10.1063/5.0143833
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Flow Rate Prediction for a Semi-permeable Membrane at Low Reynolds Number in a Circular Pipe Reviewed
Suguru Miyauchi, Shuji Yamada, Shintaro Takeuchi, Asahi Tazaki, Takeo Kajishima
Transport in Porous Media 141 ( 1 ) 185 - 199 2021.11
Authorship：Lead author, Corresponding author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC
<title>Abstract</title>A concise and accurate prediction method is required for membrane permeability in chemical engineering and biological fields. As a preliminary study on this topic, we propose the concentration polarization model (CPM) of the permeate flux and flow rate under dominant effects of viscosity and solute diffusion. In this model, concentration polarization is incorporated for the solution flow through a semi-permeable membrane (i.e., permeable for solvent but not for solute) in a circular pipe. The effect of the concentration polarization on the flow field in a circular pipe under a viscous-dominant condition (i.e., at a low Reynolds number) is discussed by comparing the CPM with the numerical simulation results and infinitesimal Péclet number model (IPM) for the membrane permeability, strength of the osmotic pressure, and Péclet number. The CPM and IPM are confirmed to be a reasonable extension of the model for a pure fluid, which was proposed previously. The application range of the IPM is narrow because the advection of the solute concentration is not considered, whereas the CPM demonstrates superior applicability in a wide range of parameters, including the permeability coefficient, strength of the osmotic pressure, and Péclet number. This suggests the necessity for considering concentration polarization. Although the mathematical expression of the CPM is more complex than that of the IPM, the CPM exhibits a potential to accurately predict the permeability parameters for a condition in which a large permeate flux and osmotic pressure occur.
DOI： 10.1007/s11242-021-01716-w
Other Link： https://link.springer.com/article/10.1007/s11242-021-01716-w/fulltext.html
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Shintaro Takeuchi, Toshiaki Fukada, Shuji Yamada, Suguru Miyauchi, Takeo Kajishima
Physical Review Fluids 6 ( 11 ) 2021.11
Language：English Publishing type：Research paper (scientific journal) Publisher：American Physical Society (APS)
DOI： 10.1103/PhysRevFluids.6.114101
Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevFluids.6.114101/fulltext
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Shuji Yamada, Shintaro Takeuchi, Suguru Miyauchi, Takeo Kajishima
Microfluidics and Nanofluidics 25 ( 10 ) 2021.9
Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC
<title>Abstract</title>A discrete-forcing immersed boundary method with permeable membranes is developed to investigate the effect of lubrication on the permeations of solute and solvent through membrane. The permeation models are incorporated into the discretisation at the fluid cells including the membrane, and discretised equations for the pressure Poisson equation and convection–diffusion equation for the solute are represented with the discontinuities at the membrane. The validity of the proposed method is established by the convergence of the numerical results of the permeate fluxes (solute and solvent) to higher-order analytical models in a lubrication-dominated flow field. As a model of the mass exchange between inside and outside of a biological cell flowing in a capillary, a circular membrane is placed between parallel flat plates, and the effect of lubrication is investigated by varying the distance between the membrane and the walls. The pressure discontinuity near the wall is larger than that at the stagnation point, which is a highlighted effect of lubrication. In the case of a small gap, the solute transport is dominated by convection inside the circular membrane and by diffusion outside. Through the time variation of the concentration in the circular membrane, lubrication is shown to enhance mass transport from/to inside and outside the membrane.
DOI： 10.1007/s10404-021-02480-5
Other Link： https://link.springer.com/article/10.1007/s10404-021-02480-5/fulltext.html
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Effect of lubrication in the non-Reynolds regime due to the non-negligible gap on the fluid permeation through a membrane Reviewed
Shintaro Takeuchi, Suguru Miyauchi, Shuji Yamada, Asahi Tazaki, Lucy T. Zhang, Ryo Onishi, Takeo Kajishima
Fluid Dynamics Research 2021.5
Language：English Publishing type：Research paper (scientific journal)
MISC 【 display / non-display 】
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Fluid-Membrane Coupling Analysis Method for Permeable Membranes with Movement and Deformation
86 ( 3 ) 105 - 107 2022.3
Authorship：Lead author, Corresponding author Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal)
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Elucidation of Mechanisms of FBG Vital Sensing by Ultrasonic-Measurement-Integrated Simulation
75 ( 12 ) P - 628-632 2019.12
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution)
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Fluid Mechanical Effects of Near Wall Blood Flow Field on Endothelial Cell Damage:Comparison of Peeling Rate of HUVEC and HAEC in Oblique Flow Load Experiment
INOUE Kosuke, HAYASE Toshiyuki, MIYAUCHI Suguru
The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2019 ( 0 ) 2G33 2019
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution) Publisher：The Japan Society of Mechanical Engineers
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Finite element analysis for flows in a tumor microenvironment considering a leakage to interstitium:Evaluation of the validity of the proposed method
TAKEDA Tomofumi, MIYAUCHI Suguru, HAYASE Toshiyuki
The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2019 ( 0 ) 2G23 2019
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution) Publisher：The Japan Society of Mechanical Engineers
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Two-dimensional fluid analysis for flows in a simple-shaped tumor capillary model considering a leakage to interstitium
MIYAUCHI Suguru, HAYASE Toshiyuki
The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2018 ( 0 ) 2F09 2018
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution) Publisher：The Japan Society of Mechanical Engineers
Presentations 【 display / non-display 】
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Computational simulation of the intracellular pressure response to action potentials using the permeation flux model for multicomponent electrolyte solution International conference
Haruhi Matsuyama, Takehiro Fujii, Suguru Miyauchi, Shintaro Takeuchi
The 76th Annual Meeting of the APS Division of Fluid Dynamics 2023.11.21
Event date： 2023.11.19 - 2023.11.21
Presentation type：Oral presentation (general)
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Hemodynamic Changes in the Left Ventricle by Bicuspid Aortic Valve Geometries International conference
Shingo Tsuda, Suguru Miyauchi, Kenichi Funamoto
The Twentieth International Conference on Flow Dynamics 2023.11.6
Event date： 2023.11.6 - 2023.11.8
Presentation type：Oral presentation (general)
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薄膜によって遮断された流路内流れ場に対する拡張有限要素法の誤差評価
島袋拓己，宮内優
日本機械学会 第36回計算力学講演会(CMD2023) 2023.10.25
Event date： 2023.10.25 - 2023.10.27
Presentation type：Oral presentation (general)
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ラグランジュ未定乗数法に基づく血管透過性の推定のためのデータ同化法（推定値の補正方法の提案）
茂零音，宮内優，竹内伸太郎，船本健一
日本機械学会 第36回計算力学講演会(CMD2023) 2023.10.26
Event date： 2023.10.25 - 2023.10.27
Presentation type：Oral presentation (general)
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Study of the mechanical effects of solvents acting on neuronal membranes using the permeation flux model of multicomponent electrolyte solution International conference
Haruhi Matsuyama, Suguru Miyauchi, Shintaro Takeuchi
ASME ‐ JSME ‐ KSME Fluids Engineering Division AJKFED 2023 2023.11.10
Event date： 2023.7.9 - 2023.7.13
Presentation type：Oral presentation (general)
Grant-in-Aid for Scientific Research 【 display / non-display 】
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多階層スケールの流動解析による赤血球と内皮グリコカリックスの力学的相互作用の解明
Grant number：19K20659 2019.04 - 2024.03
日本学術振興会 科学研究費補助金 若手研究
宮内 優
Authorship：Principal investigator
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流体と多孔質弾性体の連成解析による軟骨の変形と滲出が生体潤滑に与える影響の解明
Grant number：17K14586 2017.04 - 2020.03
日本学術振興会 科学研究費助成事業 若手研究(B) 若手研究(B)
宮内 優
Authorship：Principal investigator
本研究の目的は、生体潤滑機構解明のために関節軟骨内外の流れおよび関節軟骨の変形を考慮した流体と多孔質弾性体の連成解析手法の開発を行い、生体軟骨の変形と滲出が骨端間の流体潤滑及び摩擦特性に与える影響を定量的に明らかにすることである。本年度は、流体と弾性体の連成コードを開発し、検証問題による開発したコードの妥当性の確認と解析に適した計算設定を調べた。
流体構造連成解析に対するベンチマーク問題としてTurek and Hronが提案した、2次元矩形流路中の弾性棒の流体励起振動の解析を利用した。流体解析には移動境界問題に対する流体解析法の一つであるArbitrary Lagrange-Eulerian法を実装し、弾性体には検証問題の設定に合わせるために流体に対して透過性を有さないSt.Venant-Kirchhoffモデルを使用した。流体と弾性体の連成は強連成とした。界面の移動に対する流体メッシュの制御法には線形弾性体の平衡方程式を使用した。線形弾性体の構成式に使用されるパラメータに対する解の収束性を調べ、メッシュの歪みが小さくかつ求解の反復回数が少ない値を調査した。その結果、構成式のパラメータをポアソン比に変換した場合に、ポアソン比が0.3程度の値で最も計算が安定し、求解の反復回数が少ないことがわかった。さらに、有限要素法による流体変数の離散化に関して、流速が双線形、圧力が一定のQ1Q0要素と流速、圧力がともに双線形のQ1Q1要素の2つを用いて、計算負荷と計算精度を比較した。このベンチマーク問題に対しては、Q1Q0要素で十分にTurek and Hronの数値解と近い結果を示し、Q1Q1要素の解析に比べ、計算負荷の観点で優位であった。