研究者詳細 - 河内　俊憲

論文 - 河内　俊憲

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Experimental comparison of shock buffet on unswept and 10-deg swept wings 査読

Yosuke Sugioka, Toshinori Kouchi, Shunsuke Koike

EXPERIMENTS IN FLUIDS 63 ( 8 ) 2022年8月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

Shock wave oscillations and surface flow fields on unswept-wing and 10 deg swept-wing models were experimentally investigated in a two-dimensional transonic wind tunnel facility to clarify the effects of wing sweep on the shock buffet phenomena. High-speed shadowgraph imaging, oil flow, and unsteady pressure-sensitive paint (PSP) techniques were used to visualize the shock oscillation over the models, surface stream lines, and the surface pressure distributions, respectively. Shock waves oscillated periodically on both models under specific flow conditions, but the oscillation frequency for the 10-deg swept wing was 1.4 times higher than that for the unswept wing. A spectral analysis and a mode decomposition analysis of PSP data for the 10 deg swept-wing model showed that higher-frequency shock oscillation developed mainly on the outboard wing, where a complicated 3D surface flow structure was formed. We confirmed that the wing sweep angle is an important factor affecting characteristic Strouhal number of shock buffet according to the present data and the results of previous studies.[GRAPHICS].

DOI： 10.1007/s00348-022-03482-x

Web of Science

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Impact of Pitot tube diameter on the centre line mean flow velocity in multi-scale grid-generated turbulence 査読

Hiroto Yamaguchi, Hiroki Suzuki, Kento Tanaka, Toshinori Kouchi

Journal of Physics: Conference Series 2313 ( 1 ) 012001 - 012001 2022年7月

Development of a single-scale initial flow field into steady homogeneous turbulence with validating a constructed Fourier spectral analysis 査読

Hiroki Suzuki, Toshinori Kouchi

Journal of Physics: Conference Series 2313 ( 1 ) 012008 - 012008 2022年7月

掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing

Abstract

This study presents the development of a single-scale initial velocity field into steady homogeneous isotropic turbulence. Here, we verify a constructed Fourier spectral analysis, which is then used to approach the present issue. The present homogeneous isotropic turbulence is maintained steady by using a linear forcing scheme of Lundgren (2003). Here, two values of the primary coefficient are set here for this scheme. The initial velocity field is also set to maintain the flow globally isotropic. Temporal developments of turbulence statistics, visualization results and structure functions are examined in this study. As shown in a previous study, Rosales and Meneveau (2005), the turbulence length scale at a steady-state could remain independent of a value used for the linear forcing coefficient. The turbulence fields needed 10 to 15 times longer than the turbulence time scale to achieve this steady-state. A larger amount of time was needed for the structure functions to reach their steady-state profiles than for the turbulence statistics.

DOI： 10.1088/1742-6596/2313/1/012008

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その他リンク： https://iopscience.iop.org/article/10.1088/1742-6596/2313/1/012008/pdf

Side-Wall Effects on the Global Stability of Swept and Unswept Supercritical Wings at Buffet Conditions

Andrea Sansica, Atsushi Hashimoto, Shunsuke Koike, Toshinori Kouchi

AIAA SCITECH 2022 Forum 2022年1月

動的モード分解を用いた二次元翼バフェットの主要モードの抽出査読

福本翔太, 河内俊憲, 大寺健吾, 杉岡洋介

日本航空宇宙学会論文集 70 ( 3 ) 82 - 92 2022年

Existence of dual solutions and three-dimensional instability in helical pipe flow 査読

Anup Kumer Datta, Toshinori Kouchi, Yasutaka Hayamizu, Yasunori Nagata, Kyoji Yamamoto, Shinichiro Yanase

Chinese Journal of Physics 73 154 - 166 2021年10月

Sea-Level Static Tests of Rocket–Ramjet Combined Cycle Engine Model 査読

Sadatake Tomioka, Masao Takegoshi, Toshinori Kochi, Kanenori Kato, Toshihito Saito, Kouichiro Tani

Journal of Propulsion and Power 37 ( 3 ) 381 - 390 2021年5月

Influence of Partial Electrical Conducting Wall on Electrodynamic Flow Control 査読

NAGATA Yasunori, YAMANE Eisuke, NORII Takumi, KOUCHI Toshinori, YANASE Shinichiro

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 19 ( 1 ) 68 - 74 2021年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

The electrodynamic flow control effect using an applied magnetic field has a potential of innovative technology for aerodynamic force control of atmospheric entry vehicle because of no requirement of mechanical devices. To control this effect and aerodynamic force, we proposed a new approach using exposed electrodes on the vehicle surface. If the induced electric current is bypassed via exposed electrodes, the electromagnetic field could be changed. In this study, the influence of the partial electrical conducting wall, which is consisted of insulating and conducting walls, is numerically investigated. As a result of the MHD simulation, flow field could be changed by the vehicle surface condition. Especially, in the frontal region of the vehicle where strong Lorentz force acts, if the conducting wall is installed to electrically short to the shoulder position, the electric field within this region and the electrodynamic effect is significantly changed. Additionally, stepwise drag variation could be made by selectable shorted electrodes.

DOI： 10.2322/tastj.19.68

CiNii Article

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LESを用いた超音速乱流場における垂直噴流の混合

青木礼, 河内俊憲, 田中健人, 鈴木智也

数値流体力学シンポジウム講演論文集(CD-ROM) 35th 2020年1月

LES Analysis of Transverse Jet Mixing in Supersonic Free-stream Turbulence

Yasunori Nagata, Seitaro Yokoi, Rei Aoki, Toshinori Kouchi, Shinichiro Yanase

AIAA Scitech 2020 Forum 2020年1月

Numerical Study of the Lift Force, Velocities and Pressure Distribution of a Single Air Bubble and Two Interacting Air Bubbles Rising in Quiescent Liquid 査読

Chao Guan, Shinichiro Yanase, Koji Matsuura, Toshinori Kouchi, Yasunori Nagata

Open Journal of Fluid Dynamics 10 ( 01 ) 31 - 51 2020年

Numerical study of air-entraining and submerged vortices in a pump sump 査読

Shinichiro Yanase, Ryo Yamasaki, Toshinori Kouchi, Shunsuke Hosoda, Yasunori Nagata, Higuchi Shunji, Toshihiko Kawabe, Toshihiro Takami

IOP Conference Series: Earth and Environmental Science 240 ( 3 ) 032001 - 032001 2019年3月

Acetone-condensation nano-particle image velocimetry in a supersonic boundary layer

Toshinori Kouchi, Seiya Fukuda, Syouma Miyai, Yasunori Nagata, Shinichiro Yanase

AIAA Scitech 2019 Forum AIAA 2019-1821 2019年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：American Institute of Aeronautics and Astronautics

© 2019, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Condensation nanoparticle planar laser light scattering imaging was conducted in a suction type Mach 1.9 supersonic flow. A series of the nanoparticle image pair was obtained by using the same optical components of PIV. The velocity data were obtained by the image pairs using the image-based correlation procedure as same as PIV. Acetone vapor instead of tracer particles in a conventional PIV was added to a mainstream gas in a reservoir. Acceleration process through a Laval nozzle automatically generated condensation particles of the acetone which were uniformly seeded into the entire flowfield. The increase in the additive concentration increased the number density of the particle and enabled a detail visualization of the vortex structures in the boundary layer. The increase in the additive concentration also increased the mean molecular weight of the acetone-seeded air. This decreased the flow speed. However, this is not a big matter because the heat release due to the condensation was negligible and the decrease in the flow speed was easily predicted from the thermodynamic properties of the gas. The particle size was difficult to be measured directly, so the tracer response time was estimated by the oblique shock test. The Stokes diameter of the particle was estimated to be 160 nm. Such a small diameter particle provides high traceability resulting in capturing shock wave with a few vector spacing and also provides high spatial resolution image resulting in capturing sub-mm scale vortices within the boundary layer. The mean and turbulent velocity fields evaluated from such high spatially and temporally resolved image pairs fairly agreed with previous measurement in the boundary layer.

DOI： 10.2514/6.2019-1821

Scopus

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Hydrodynamic instability with convective heat transfer through a curved channel with strong rotational speed

Mohammad Sanjeed Hasan, Rabindra Nath Mondal, Toshinori Kouchi, Shinichiro Yanase

AIP Conference Proceedings 2121 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：AIP Publishing

In this paper, a comprehensive numerical study on viscous incompressible fluid flow and heat transfer through a loosely coiled square duct has been presented. Spectral method is used as a basic tool to solve the system of non-linear partial differential equations. Numerical calculations are carried out for the Dean number Dn = 1000 with a temperature difference across the vertical sidewalls for the Grashof number Gr = 100, where the outer wall is heated and the inner wall cooled. A rotation of the duct about the center of curvature is imposed in the positive direction for the Taylor number 0 <= Tr <= 2000 and combined effects of the centrifugal, Coriolis and buoyancy forces are investigated. First, steady solutions are obtained by the Newton-Raphson iteration method. As a result, three branches of asymmetric steady solutions with two- to four-vortex solutions are obtained. Then, time evolution calculations as well as power spectrum density of the unsteady solutions are obtained and it is found that the unsteady flow undergoes through various flow instabilities, if Tr is increased in the positive direction. Nusselt numbers are calculated as an index of convective heat transfer, and it is found that convective heat transfer is significantly enhanced by the secondary flow. Finally, a comparison between the numerical and experimental investigations has been provided. It is found that there is a good agreement between the numerical and experimental investigations.

DOI： 10.1063/1.5115851

Web of Science

Scopus

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VSL解法の電磁ヒートシールド解析への拡張査読

永田靖典, 石原遼一, 前田真吾, 河内俊憲, 柳瀬眞一郎

日本航空宇宙学会論文集 67 ( 1 ) 16 - 24 2019年

記述言語：日本語出版者・発行元：一般社団法人日本航空宇宙学会

<p>The electrodynamic heat shield is new type of heat protection system for atmospheric-entry vehicle, which utilizes the Lorentz force acting on the weakly ionized plasma flow inside the shock layer. A huge amount of calculation is necessary to estimate overall effect of the electrodynamic heat shield, because its effect interacts with the atmospheric-entry trajectory. In the present study, the Viscous Shock Layer (VSL) analysis method for electrodynamic heat shield is proposed for the quick analysis, which can calculate much faster than Navier-Stokes (NS) simulation. For this purpose, the VSL equations for the electrodynamic heat shield analysis are introduced under the ideal gas assumption, including circumferential momentum equation and Maxwell equations. The new method is also proposed to solve the new VSL equations. By the comparison to the NS simulation, the new VSL method gives good estimations of drag force and wall heat flux for wide ranges of interaction parameter and Hall parameter although the slight difference of wall heat flux at the stagnation point is observed. Therefore, the present VSL method could be applicable to the estimation tool of the electrodynamic heat shield effect. </p>

DOI： 10.2322/jjsass.67.16

CFD Simulation of an Ejector-jet Engine 査読

Hiromu Inoue, Toshinori Kouchi, Yasunori Nagata, Shinichiro Yanase

Asia-pacific International Symposium on Aerospace Technology 2019 APISAT-733 2019年

静止流体中の鉛直壁面近傍を上昇する単一球形気泡の修正Force-coupling Methodによる数値解析査読

関超, 柳瀬眞一郎, 松浦宏治, 河内俊憲, 永田靖典

ながれ : 日本流体力学会誌 = Nagare : journal of Japan Society of Fluid Mechanics 37 ( 3 ) 281 - 289 2018年6月

LES Investigation of Supersonic Mixing Layer Using Different Type of Gas

Tatsuya Kishi, Toshinori Kouchi, Yasunori Nagata, Shinichiro Yanase

Asian Joint Conference on Propulsion and Power 2018 AJCPP2018-035 2018年

Laminar forced convective heat transfer in helical pipe flow 査読

Anup Kumer Datta, Shinichiro Yanase, Toshinori Kouchi, Mohammed M.E. Shatat

International Journal of Thermal Sciences 120 41 - 49 2017年10月

Numerical Study of Turbulent Helical Pipe Flow With Comparison to the Experimental Results 査読

Anup Kumer Datta, Yasutaka Hayamizu, Toshinori Kouchi, Yasunori Nagata, Kyoji Yamamoto, Shinichiro Yanase

Journal of Fluids Engineering 139 ( 9 ) 2017年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ASME International

Turbulent flow through helical pipes with circular cross section is numerically investigated comparing with the experimental results obtained by our team. Numerical calculations are carried out for two helical circular pipes having different pitches and the same nondimensional curvature δ (=0.1) over a wide range of the Reynolds number from 3000 to 21,000 for torsion parameter β (=torsion /2δ = 0.02 and 0.45). We numerically obtained the secondary flow, the axial flow and the intensity of the turbulent kinetic energy by use of three turbulence models incorporated in OpenFOAM. We found that the change to fully developed turbulence is identified by comparing experimental data with the results of numerical simulations using turbulence models. We also found that renormalization group (RNG) k−ε turbulence model can predict excellently the fully developed turbulent flow with comparison to the experimental data. It is found that the momentum transfer due to turbulence dominates the secondary flow pattern of the turbulent helical pipe flow. It is interesting that torsion effect is more remarkable for turbulent flows than laminar flows.

DOI： 10.1115/1.4036477

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論文 - 河内　俊憲