研究者詳細 - 内山　知実

論文 - 内山　知実

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出川智啓, 谷強, 内山知実

年次大会 2018 巻 ( 0 ) 頁： S0510105 2018年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本機械学会

In the present study, we propose a method for calculating the fluid dynamic forces acting on bodies in a two-dimensional simulation of a flow around a moving body by using the vortex–in–cell method. The body is represented using the volume penalization method which introduces the influence of the body on the flow as an external force in the form of a penalization term into the Navier–Stokes equation. The pressure field is computed by solving the Poisson equation, which is derived by obtaining the divergence of the Navier-Stokes equation. The pressure and viscous stress on the body surface are obtained from a quadratic function along the vector normal to the surface. A flow around a circular cylinder oscillating in still water is simulated, and the fluid dynamic force acting on the cylinder is calculated using the proposed method. The velocity profiles across four cross-sections at three different time points agree well with the results of a measurement conducted using a laser Doppler velocimeter. The in-line force acting on the cylinder agrees with the results of the simulations performed using the boundary-conforming formulation.

DOI： 10.1299/jsmemecj.2018.s0510105

CiNii Research

Numerical simulation of jet issuing diagonally upward into density-stratified fluid in cylindrical tank 査読有り

Degawa, T, Uchiyama, T, Aozasa, I, Ishikawa, A, Motoyama, K

J. Power and Energy Eng. 6 巻 ( 3 ) 頁： 38-52 2018年

Control of air bubble cluster by a vortex ring launched into still water 査読有り

Uchiyama, T, Kusamichi, S

Int. J. Chemical Engineering and Applications 8 巻 ( 1 ) 頁： 37-46 2017年

密度成層流体中に射出された複数の渦輪による撹拌の数値シミュレーション

出川智啓, 内山知実

年次大会 2017 巻 ( 0 ) 頁： S0520405 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本機械学会

This study numerically investigates the mixing of a two-layer density stratified fluid caused by vortex rings. Initially, the density-stratified fluid is in a static condition in a tank. The upper and lower fluids are glycerol aqueous solution and an aqueous solution of potassium dihydrogen phosphate, respectively. Two vortex rings are arranged on a vertical line in the lower fluid, and the axial interval is 80 mm. The diameter of the vortex ring is 26.4 mm, and the Reynolds numbers based on the circulation are 4000, 6000, and 8000. The vortex rings are launched simultaneously in the vertically upward direction. The simulation explores the collision of the vortex rings with the density interface, the entrainment of the fluids into the vortex rings, and the resulting mixing between the fluids. It also clarifies the behavior of each vortex ring, such as the deformation and the interaction with the density interface.

DOI： 10.1299/jsmemecj.2017.s0520405

CiNii Research

密度界面に衝突する渦輪の数値シミュレーション

伊藤丈矩, 出川智啓, 内山知実, 角田博之

年次大会 2017 巻 ( 0 ) 頁： S0520406 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本機械学会

This study simulates the behavior of a vortex ring launched toward the interface of a two-layer density stratified fluid and the resulting mixing phenomena between the fluids. Initially, the density-stratified fluid is in a static condition in a tank. The upper and lower fluids are glycerol aqueous solution and an aqueous solution of potassium dihydrogen phosphate, respectively. The vortex ring with a diameter of 26.4 mm is launched vertically downward from the upper fluid region. It travels by the vertical motion toward the density interface. The Reynolds number, based on the circulation of the vortex ring, is 3500. The simulation conditions are parallel with an experimental work of one of the authors. The vortex in cell method, which was presented by the authors for flow simulations of two-layer density stratified fluid in a prior study, is used. The simulation favorably highlights the collision, deformation and penetration of the vortex ring at the density interface. It also successfully reveals the mixing between the upper and lower fluids induced by the motion of the vortex ring. These simulated results are discussed by comparing with the corresponding experimental ones.

DOI： 10.1299/jsmemecj.2017.s0520406

CiNii Research

Behavior of a jet issuing diagonally upward into two-layer density-stratified fluid in a cylindrical tank 査読有り

Degawa, T, Fukue, S, Uchiyama, T, Ishikawa, A, Motoyama, K

J. Flow Control, Measurement & Visualization 5 巻頁： 51-64 2017年

Generation and transport of solid particle clusters using a vortex ring launched into water 査読有り

Uchiyama, T, Yano, C, Degawa, T

Int. J. Chemical Engineering and Applications 8 巻 ( 4 ) 頁： 253-260 2017年

渦輪を用いた固体粒子群の生成・輸送技術の開発

内山知実

ホソカワ粉体工学振興財団年報 25 巻 ( 0 ) 頁： 26 - 32 2017年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益財団法人ホソカワ粉体工学振興財団

渦輪を用いた固体粒子群の生成と輸送の技術の開発実験を実施した．ピストンとシリンダから構成される渦輪射出装置を水タンクの底部に設置し，シリンダ出口に張ったメッシュにポリアセタール粒子を置いた．個数は100，直径は1.52 mm，密度は1417 kg/m3である．シリンダ内の水をピストンで鉛直上方に押し上げ，タンク内に固体粒子を含む渦輪を射出した．ピストン速度とシリンダ直径で定義されるReynolds数Reが6500，7500，13000の渦輪を調べた．その結果，Re = 7500と13000の場合には，粒子が渦輪内部に巻き込まれて粒子群が生成され，渦輪の移流に伴って鉛直上方へ輸送された．渦輪の鉛直断面内の水速度は粒子により低下し，渦輪強度も減じた．Reが低い場合ほど低下量が大であった．

DOI： 10.14356/hptf.15102

CiNii Research

A Feasibility Study of Power Generation from Sewage Using a Hollowed Pico-Hydraulic Turbine

Uchiyama Tomomi, Honda Satoshi, Okayama Tomoko, Degawa Tomohiro

ENGINEERING 2 巻 ( 4 ) 頁： 510 - 517 2016年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Engineering

This study is concerned with the feasibility of power generation using a pico-hydraulic turbine from sewage flowing in pipes. First, the sewage flow rate at two connection points to the Toyogawa River-Basin Sewerage, Japan, was explored for over a year to elucidate the hydraulic energy potential of the sewage. Second, the performance of the pico-hydraulic turbine was investigated via laboratory experiments that supposed the turbine to be installed in the sewage pipe at the connection points. This study indicates that the connection points have hydraulic potential that can be used for power generation throughout the year. It also demonstrates that the pico-hydraulic turbine can be usefully employed for power generation from sewage flowing in the pipe at the connection points.

DOI： 10.1016/J.ENG.2016.04.007

Web of Science

Scopus

Numerical simulation of the interactions between a vortex ring and solid particles suspended above a horizontal wall

Uchiyama Tomomi, Shimada Seiji

POWDER TECHNOLOGY 301 巻頁： 966 - 980 2016年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Powder Technology

The interactions between a vortex ring and solid particles near a horizontal wall in the air are explored in this study using numerical simulations. The vortex ring is moved toward the particles initially arranged in layers above the wall. The Reynolds number of the vortex ring is 1146. When the Stokes number St is 0.1, the particles initially arranged around the central axis of the vortex ring are driven toward the wall while moving in the radial direction. They distribute circularly along the outer edge of the particle cluster on the wall. The particles near the layer's edge are whirled up. Three-dimensional vortex structures, including secondary and tertiary vortex rings, are produced around the particles. When St = 1, vortical flows induced around the particles appear in the broader region. They reduce rapidly owing to the motion of particles relative to the wall (collision and rebound). The drag force acting on the particles lowers the strength of the vortex ring and also suppresses the approach of the vortex ring toward the wall.

DOI： 10.1016/j.powtec.2016.07.042

Web of Science

Scopus

Numerical simulation of flow around two tandem cylinders by vortex in cell method combined with immersed boundary method

Van Luc N., Zuhal L.R., Uchiyama T.

Advances and Applications in Fluid Mechanics 19 巻 ( 4 ) 頁： 787 - 810 2016年10月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Advances and Applications in Fluid Mechanics

This study is concerned with the numerical simulation of incompressible flows around two circular cylinders in tandem arrangement. A vortex in cell (VIC) method combined with an immersed boundary (IB) method is applied to the simulation. The Reynolds number Re, based on the diameter D of cylinder and the flow velocity upstream of the front cylinder, ranges from 200 to 9500. The distance L between the cylinders is varied from 1.5D to 8D. The simulated flow characteristics, such as the behavior of the shear layers separated from the cylinders, the vortex shedding and the fluid forces acting on the cylinders, are favorably compared with the existing results. The simulation can also successfully analyze the effects of Re and L on the flow characteristics. These simulation results demonstrate that the VIC method combined with the IB method is usefully applicable to the simulation of incompressible flows around two tandem cylinders.

DOI： 10.17654/FM019040787

Scopus

Study of the interactions between rising air bubbles and vortex core of swirling water flow around vertical axis

Uchiyama Tomomi, Ishiguro Yukihiro

CHEMICAL ENGINEERING SCIENCE 142 巻頁： 137 - 143 2016年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Engineering Science

The interactions between rising air bubbles and the vortex core of swirling water flows in a cylindrical tank are experimentally investigated. A stirring disc mounted at the center of the tank bottom is rotated to produce swirling water flows around the central (vertical) axis of the tank, and small air bubbles are successively released from tubules mounted near the stirring disc. The bubbles rise helically in the swirling water flow because of the buoyancy force, and some bubbles are entrained into the vortex core. The precessional amplitude of the vortex core is enhanced by the bubbles when the bubble flow rate Qg is very low. But it decreases with increasing Qg when Qg is larger than a certain value. In the horizontal cross-sections near the stirring disc, the bubbles make the water flow field nonaxisymmetric and reduce the water velocity. The water velocity variation due to the bubbles affects the shape of the vortex funnel formed at the water surface.

DOI： 10.1016/j.ces.2015.11.042

Web of Science

Scopus

Experimental study of flow around a circular cylinder inside a bubble plume 査読有り

Uchiyama, T, Ishiguro, Y

Advances in Chem. Eng. Sci. 6 巻頁： 269-280 2016年

Effects of clearance between rotor and ground on the performance of an open cross-flow-type nano-hydraulic turbine 査読有り

Uchiyama, T, Mizoguchi, S, Iio, S, Katayama, Y, Ikeda, T

J. Energy and Power Engineering 10 巻頁： 465-473 2016年

Cahn-Hilliard方程式に対する格子ボルツマン法の精度評価

瀬田剛, 内山知実, 高野登

計算力学講演会講演論文集 2016.29 巻 ( 0 ) 頁： 050 2016年

A feasibility study of power generation from sewage using a hollowed pico-hydraulic turbine 査読有り

Uchiyama, T, Honda, T, Okayama, T, Degawa, T

Engineering 2 巻頁： 510-517 2016年

Numerical simulation of the interactions between a vortex ring and solid particles suspended above a horizontal wall 査読有り

Uchiyama, T, Shimada, S

Powder Technology 301 巻頁： 966-980 2016年

円筒容器内の密度成層流体に対する斜め噴流による混合の数値シミュレーション

内山知実, 青笹功, 石川明, 本山浩二

流体工学部門講演会講演論文集 2016 巻 ( 0 ) 頁： 0207 2016年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本機械学会

Mixing phenomena, induced by a jet issued diagonally upward into a two-layer densitystratified fluid in a cylindrical tank, are numerically simulated. The upper and lower fluids are water and a NaCl aqueous solution, respectively. The mass concentration of the NaCl-water solution is 0.02. The lower fluid is issued from a nozzle mounted on the tank bottom. The angle of the nozzle to the tank bottom is 60 degree, and the Reynolds number defined by the jet velocity and the nozzle diameter ranges from 475 to 3089. The simulation highlights the jet behavior relative to the density interface and the resultant mixing phenomena.

DOI： 10.1299/jsmefed.2016.0207

CiNii Research

Study of the interactions between rising air bubbles and vortex core of swirling water flow around vertical axis 査読有り

Uchiyama, T, Ishiguro, Y

Chemical Engineering Science 142 巻頁： 137-143 2016年

SIMULATION OF JET ISSUED INTO TWO-LAYER DENSITY-STRATIFIED FLUID BY VORTEX IN CELL METHOD COMBINED WITH IMMERSED BOUNDARY METHOD

Aozasa, I; Uchiyama, T

PROCEEDINGS OF THE ASME/JSME/KSME JOINT FLUIDS ENGINEERING CONFERENCE, 2015, VOL 1A, SYMPOSIA, PT 2 2016年

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