研究者詳細 - 西野　耕一

<p>When high purity and large diameter are desired in manufacturing single crystals, defects due to “oscillatory thermocapillary” are inevitable in the crystal. The oscillatory convection is caused by “Hydrothermal wave instability”. We performed the tomographic stereo PIV on thermocapillary flows with thin liquid films for understanding the three dimensonal structure of Hydrothermal waves. As a result, the flow structure of Hydrothermal wave was captured and reconstructed sucsessfully.</p>

Comparative Analysis of PIV and CFD Results for Unsteady Thermocapillary Convection in Thin-film Liquids

Kudo Masaki, Nakagawa Hiroyuki, Nishino Koichi

MICROGRAVITY SCIENCE AND TECHNOLOGY 33 ( 5 ) 63-1 - 63-9 2021年10月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

オイルミストセパレータにおける微小液滴の壁面付着量及び流動特性に関する数値解析

木村優介, 島伸一郎, 西野耕一, 山本翔太, 中島聖, 西村真人, 幸徳正信

中国四国支部総会・講演会　講演論文集 2021.59 ( 0 ) 06b1 2021年

DOI CiNii Research

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共著

Numerical study on the effects of convective and radiative heat transfer on thermocapillary convection in a high-Prandtl-number liquid bridge in weightlessness

Yano Taishi, Nishino Koichi

ADVANCES IN SPACE RESEARCH 66 ( 8 ) 2047 - 2061 2020年10月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Turbulence energetics in an axisymmetric impinging jet flow

Chandra Shekhar and Koichi Nishino

Physics of Fluids 31 ( 055111 ) 055111-1 - 055111-20 2019年5月 [査読有り]

DOI

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

その他リンク： https://aip.scitation.org/doi/10.1063/1.5086949

Flow Visualization of Axisymmetric Steady Marangoni Convection in High-Prandtl-Number Liquid Bridges in Microgravity

YANO Taishi, NISHINO Koichi

International Journal of Microgravity Science and Application 36 ( 2 ) 2019年4月

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：日本マイクログラビティ応用学会共著

Microgravity experiments on Marangoni convection in a liquid bridge of high-Prandtl-number fluid so-called Marangoni Experiment in Space (MEIS) and Dynamic Surf (DS) were performed on board the International Space Station (ISS) to understand the Marangoni convection instability. This study reports the internal flow patterns and velocity profiles of the axisymmetric steady Marangoni convection observed in these projects for various Prandtl numbers (Pr = 67, 112 and 207), and for various liquid bridge geometries. The classical three-dimensional particle tracking velocimetry (3-D PTV) is customized for the microgravity experiments, and the spatial structures of the Marangoni convection in liquid bridges are measured with good accuracy. The details of the measurement method currently used, and the results of the 3-D PTV are discussed in this study.

その他リンク： https://ci.nii.ac.jp/naid/130007760923

Effect of radiative heat transfer on thermocapillary convection in long liquid bridges of high-Prandtl-number fluids in microgravity

Shitomi Nobuhiro, Yano Taishi, Nishino Koichi

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 133 405 - 415 2019年4月

DOI Web of Science

記述言語：日本語掲載種別：研究論文（学術雑誌）共著

Turbulence characteristics of radially-confined impinging jet flows

C Shekhar,K Nishino

International Journal of Heat and Fluid Flow 75 278 - 299 2019年2月 [査読有り]

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Effect of interfacial heat transfer on basic flow and instability in a high-Prandtl-number thermocapillary liquid bridge

T Yano, M Hirotani, K Nishino

International Journal of Heat and Mass Transfer 125 1121 - 1130 2018年10月 [査読有り]

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Convective mixing of miscible liquids in a rotor-stator spinning disk reactor

Hitoshi Toma and Koichi Nishino

Chemical Engineering Journal 346 329 - 339 2018年8月 [査読有り]

DOI

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

Convective mixing of two miscible liquids injected into a rotor-stator spinning disk reactor (RS-SDR) has been
studied using an LIF technique and CFD simulations. The fluids are ammonia water and fluorescein ammonia
water solutions. The RS-SDR has a rotor 100mm in diameter and a thin circular cavity 0.10–0.15mm in height
between the rotor and stator. Laminar flow conditions for rotation speeds up to 120 rpm and total flow rates up
to 8 mL/min are considered. The fluorescein solution is injected from the second off-center hole into the cavity
filled with the ammonia water supplied from the central hole. The LIF technique visualizes a spiral streak pattern
formed downstream of the second injection hole. This streak pattern is analyzed to calculate the local mixedness
of the two fluids. It is determined that the mixedness increases for lower flow rates, while it is less sensitive to
rotation speed and cavity height. The CFD simulations indicate that the spiral streak pattern is deformed and
stretched in the radial direction to form a densely layered structure of the two fluids. The development of the
mixedness along the streak pattern is correlated well with Reinlet/Recavity, where Reinlet and Recavity are the Reynolds
numbers for the injected flow and the azimuthal flow in the cavity, respectively. This Reynolds number ratio is
shown to be related to the Rossby number and the position and radius of the second injection hole. The proposed
correlation is based on a linear combination of injection mixing and rotation mixing. The mixedness decreases
with Reinlet/Recavity because the injection mixing decreases with Reinlet while the rotation mixing increases with
Recavity.

その他リンク： https://www.sciencedirect.com/science/article/pii/S1385894718305655

Terrestrial and microgravity experiments on onset of oscillatory thermocapillary-driven convection in hanging droplets

Takumi Watanabe, Tomohiko Takakusagi, Ichiro Ueno, Hiroshi Kawamura, Koichi Nishino, Mitsuru Ohnish … 全著者表示

International Journal of Heat and Mass Transfer 123 945 - 9556 2018年8月 [査読有り]

DOI

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

Thermocapillary-driven convection in a hanging droplet is experimentally investigated under normal- and micro-gravity conditions. A droplet is hung on a heated cylindrical rod facing downward, and another rod cooled is placed just beneath the droplet to create the designated temperature difference between both ends of the droplet. A transition of the flow field from a two-dimensional axisymmetric `steady' flow to three-dimensional time-dependent `oscillatory' ones by increasing temperature difference is realized. The oscillatory flow is accompanied with thermal waves due to so-called hydrothermal wave (HTW) instability, which propagates over the free surface at a constant frequency. The present study aims to understand the transition conditions of the flow from the steady to the oscillatory ones, and to characterize the convective field inside the droplet with the HTW by imposing a range of temperature differences. We discuss the transition condition and the flow fields in the oscillatory regimes after the transition obtained in the terrestrial and on-orbit experiments in `Kibo,' the Japanese Experiment Module aboard the International Space Station.

その他リンク： https://www.sciencedirect.com/science/article/pii/S0017931018308652?via%3Dihub

Report on Microgravity Experiments of Dynamic Surface Deformation Effects on Marangoni Instability in High-Prandtl-Number Liquid Bridges

Taishi Yano, Koichi Nishino, Satoshi Matsumoto, Ichiro Ueno, Atsuki Komiya, Yasuhiro Kamotani and N … 全著者表示

Microgravity-Science and Technology 2018年4月 [査読有り]

DOI

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 共著

This paper reports an overview and some important results of microgravity experiments called Dynamic Surf, which have
been conducted on board the International Space Station from 2013 to 2016. The present project mainly focuses on the
relations between the Marangoni instability in a high-Prandtl-number (Pr = 67 and 112) liquid bridge and the dynamic free
surface deformation (DSD) as well as the interfacial heat transfer. The dynamic free surface deformations of large-scale
liquid bridges (say, for diameters greater than 10 mm) are measured with good accuracy by an optical imaging technique. It
is found that there are two causes of the dynamic free surface deformation in the present study: the first is the time-dependent
flow behavior inside the liquid bridge due to the Marangoni instability, and the second is the external disturbance due to the
residual acceleration of gravity, i.e., g-jitter. The axial distributions of DSD along the free surface are measured for several
conditions. The critical parameters for the onset of oscillatory Marangoni convection are also measured for various aspect
ratios (i.e., relative height to the diameter) of the liquid bridge and various thermal boundary conditions. The characteristics
of DSD and the onset conditions of instability are discussed in this paper.

その他リンク： https://link.springer.com/article/10.1007/s12217-018-9614-9

Overview of “Dynamic Surf” Project in Kibo–Dynamic Behavior of Large-Scale Thermocapillary Liquid Bridges in Microgravity

Taishi YANO, Koichi NISHINO, Satoshi MATSUMOTO, Ichiro UENO, Atsuki KOMIYA, Yasuhiro KAMOTANI and N … 全著者表示

International Journal of Microgravity Science and Application 35 ( 1 ) 23456 - 1 - 23456-7 2018年4月 [査読有り]

DOI

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 of Microgravity Application 共著

This paper reports the overview of Dynamic Surf project conducted in the Japanese Experiment Module Kibo on board the International Space
Station (ISS), especially focusing on the experimental conditions, the measurement systems, and the g-jitter effects. Oscillatory Marangoni
convection in the liquid bridge is associated with oscillatory motion of the liquid-gas interface due to velocity oscillation inside the liquid bridge,
where such a motion is called dynamic surface deformation (DSD). The present project aims at understanding the DSD effect in the transition
mechanisms of temperature gradient-driven Marangoni convection in large-scale liquid bridges of high-Prandtl-number fluids through the longterm
microgravity experiments on board the ISS. A series of microgravity experiments have been conducted in the period from September 2013
to November 2016 to understand the instability mechanisms and the role of DSD in Marangoni convection.

その他リンク： http://www.jasma.info/journal/wp-content/uploads/sites/2/2018/01/2018_p350102.pdf

Sensitivity of hydrothermal wave instability of Marangoni convection to the interfacial heat transfer in long liquid bridges of high Prandtl number fluids

T. Yano, K. Nishino, I. Ueno, S. Matsumoto, and Y. Kamotani

Physics of Fluids 29 ( 044105 ) 044105 - 1 - 044105-11 2017年3月 [査読有り]

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Institute of Physics 共著

This paper reports the sensitivity of hydrothermal wave (HTW) instability of Marangoni convection to the interfacial heat transfer of Marangoni convection in liquid bridges (LBs) of high Prandtl number fluids (Pr=67, 112 and 207) formed under the microgravity environment on the International Space Station. The data for instability are collected for a wide range of AR and for TC=15 and 20 degC, where AR is the aspect ratio (=height/diameter) of the LB and TC is the cooled disk temperature. A significant decrease in critical oscillation frequency as well as an appreciable decrease in the critical Marangoni number is observed for AR>1.25. This drastic change of instability mechanisms is associated with the reversal of axial traveling direction of HTWs and roll-structures as reported previously. It is found that this reversal is closely related to the interfacial heat transfer, which is evaluated numerically through accounting for both convective and radiative components. A heat transfer ratio, QI/QH, is introduced as a dimensionless parameter for interfacial heat transfer, where QI and QH are the heat transfer rates at the LB-gas and LB-disk interfaces, respectively. It is revealed that HTWs travel in the same direction as the surface flow for QI/QH>0 (heat-loss condition) while in the opposite direction for QI/QH<0 (heat-gain condition). It is shown that the heat-transfer condition alters slightly but appreciably the basic temperature and flow field, the alteration that is not accounted for in the previous linear stability analyses for an infinite LB.

その他リンク： http://aip.scitation.org/doi/10.1063/1.4979721

Effect of ambient gas flow on the instability of Marangoni convection in liquid bridges of various volume ratios

Taishi Yano, Kaname Maruyama, Takuya Matsunaga, Koichi Nishino

International Journal of Heat and Mass Transfer 99 182 - 191 2016年8月 [査読有り]

DOI Web of Science

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

液柱マランゴニ対流の不安定性に与える周囲気体流動の影響を、幅広い体積比について実験的に求め、数値解析結果を援用しながら、液柱表面からの熱損失と不安定性の関係を報告した論文。高プラントル数流体であるシリコーンオイルを作動流体とし、直径5mmの対向する加熱・冷却ディスクの間に液柱を形成し、ディスク間温度差に駆動されるマランゴニ対流（＝表面張力流）の不安定性（振動流遷移、カオス・乱流化）を実験的に測定した。

その他リンク： http://www.sciencedirect.com/science/article/pii/S0017931015307298

モータリングエンジン筒内気流のサイクル間変動に関する研究－PIV計測とLESの比較検証－

沢田龍作, 小池竜治, 西野耕一

自動車技術会論文集 47 ( 3 ) 711 - 716 2016年5月 [査読有り]

DOI

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：日本自動車技術会共著

モータリング駆動される可視化エンジンの筒内流動に発生するサイクル間変動の特性を、複雑乱流計測に適したダイナミックステレオPIVを用いて測定した結果を報告したもの。非定常乱流の数値解析手法として期待されているLESを用いた解析を行い、実験結果を妥当に予測できることを示した。実験結果およびLES結果は、スワール比とタンブル比に顕著なサイクル間変動が発生し、それが圧縮上死点まで残存していることを明らかにした。

その他リンク： https://www.bookpark.ne.jp/cm/jsae/search.asp

Transition to chaotic thermocapillary convection in a half zone liquid bridge

Taiki Matsugasea, Ichiro Ueno, Koichi Nishino, Mitsuru Ohnishi, Masato Sakurai, Satoshi Matsumoto, … 全著者表示

International Journal of Heat and Mass Transfer 89 903 - 912 2015年10月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

国際宇宙ステーションの微小重力環境を利用して大直径液柱を形成し、それを対象とした液柱マランゴニ対流の不安定性（即ち、カオス流・乱流への遷移）を実験的に明らかにしたもの。液柱表面近傍の熱電対からの温度シグナルを対象として、リヤプノフ指数や平行移動誤差を用いたカオス解析を施した結果、ディスク間温度差を上昇させた条件において、対流場がカオス化していることが示された。

その他リンク： http://www.sciencedirect.com/science/article/pii/S0017931015005323

Modeling of the experiments on the Marangoni convection in liquid bridges in weightlessness for a wide range of aspect ratio

Denis E. Melnikov, Valentina M. Shevtsova, Taishi Yano and Koichi Nishino

the International Journal of Heat and Mass Transfer 87 119 - 127 2015年8月 [査読有り]

DOI Web of Science

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

微小重力環境で得られた高プラントル数液柱マランゴニ対流の振動流遷移について、直接数値計算による比較を行い、気液界面における熱損失の影響を論じたもの。気液界面における熱損失をビオー数を介した第三種境界条件で与えることにより、実験結果と妥当に一致する数値解析結果を得た。その境界条件は、比較的短い液柱について影響が大きく、比較的長い液柱については影響が小さいことを示した。温度差駆動の表面張力流の不安定性に対して、気液界面の熱的境界条件が大きな影響を与えていることを明らかにした。

その他リンク： http://www.sciencedirect.com/science/article/pii/S0017931015002744#

Effect of liquid bridge shape on the oscillatory thermal Marangoni convection

Taishi Yano and Koichi Nishino

The European Physical Journal Special Topics 224 ( 2 ) 289 - 298 2015年4月 [査読有り]

DOI Web of Science

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 共著

温度差駆動の液柱マランゴニ対流の振動流遷移に与える液柱のアスペクト比と体積比の影響を系統的な地上実験で明らかにした結果をまとめた論文。アスペクト比と体積比の影響について、一つの無次元数であるSDRによって説明できることを示した。

その他リンク： http://link.springer.com/article/10.1140/epjst/e2015-02360-8

Instability of thermocapillary convection in long liquid bridges of high Prandtl number fluids in microgravity

2. Koichi Nishino, Taishi Yano, Hiroshi Kawamura, Satoshi Matsumoto, Ichiro Ueno and Michael K. Erm … 全著者表示

Journal of Crystal Growth 420 57 - 63 2015年3月 [査読有り]

DOI Web of Science

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

国際宇宙ステーションの微小重力環境において、温度駆動される液柱マランゴニ対流の不安定性（振動流、カオス流れ、乱流への遷移現象）を系統的な実験で明らかにした内容をまとめたもの。地上では実現できない大きな液柱アスペクト比（最大液柱長＝ディスク直径の約2倍）に対する実験データを取得した。

その他リンク： http://www.sciencedirect.com/science/article/pii/S0022024815002353

Instability and associated roll structure of Marangoni convection in high Prandtl number liquid bridge with large aspect ratio

T. Yano, K. Nishino, H. Kawamura, I. Ueno, and S. Matsumoto

Physics of Fluids 27 ( 2 ) 024108 - 1 - 024108-13 2015年2月 [査読有り]

DOI Web of Science

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

微小重力環境で得られた温度差駆動の液柱マランゴニ対流の不安定性を対象として、流れ場の三次元計測結果に基づいて、渦状のロール構造の出現と特性についてまとめたもの。液柱アスペクト比が1.25未満の短い液柱ではロール構造が表面流と同じ方向に伝播するのに対して、長い液柱では逆方向に伝播することを実験的に見いだした。そのような逆方向伝播およびロール構造の特性は、無限長液柱を仮定した線形安定性解析の結果と合致することを示した。

その他リンク： http://scitation.aip.org/content/aip/journal/pof2/27/2/10.1063/1.4908042

Oscillation and heat transfer in upward laminar impinging jet flows

Chandra Shekhar and Koichi Nishino

International Journal of Heat and Fluid Flow 50 316–329 2014年12月 [査読有り]

DOI

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

水を作動流体とする鉛直上向き衝突噴流を対象として、衝突壁の加熱に起因する流れ場・温度場の振動流状態の発生について、数値解析によって明らかにしたもの。衝突壁における流れのはく離の様子がリチャードソン数によって整理され、それが余り大きくない条件において振動流状態が生じることを示した。振動流状態になると、壁面熱伝達率や壁面摩擦係数も振動し、その特性を定量的に示した。

その他リンク： http://www.sciencedirect.com/science/article/pii/S0142727X14001076

粒子画像流速測定法と渦運動エネルギーを用いた回転水槽実験で発生する傾圧不安定波の定量化

筆保弘徳, 舛田あゆみ, 乙部直人, 熊澤里枝, 西野耕一

ながれマルチメディア 33 ( 6 ) 549 - 550 2014年10月 [査読有り]

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：一般社団法人日本流体力学会共著

回転水槽実験に発生する傾圧不安定波を対象として、水面の運動を粒子画像流速計（PIV）を用いて計測した結果をまとめたもの。水面の運動を平均場と渦度場のエネルギーに分解し、後者にフーリエ解析を適用して波数別渦運動エネルギーを算出することによって、傾圧不安定波の定量的は同定を行った。

その他リンク： http://www.nagare.or.jp/publication/mm/archive/2014.html

The JEREMI-project on thermocapillary convection in liquid bridges, Part B: overview on impact of co-axial gas flow

V. Shevtsova, Y. Gaponenko, H. C. Kuhlmann, M. Lappa, M. Lukasser, S. Matsumoto, A. Mialdun, J. M. … 全著者表示

Fluid Dynamics & Materials Processing 10 ( 2 ) 197 - 240 2014年 [査読有り]

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）共著

温度差駆動の液柱マランゴニ対流の不安定性に対する液柱周囲流動の影響を対象として、実験と数値解析による日欧共同研究の成果をまとめたもの。この共同研究は、計画されている国際宇宙ステーションでの微小重力実験の準備の一環として実施されたものである。

その他リンク： http://www.techscience.com/doi/10.3970/fdmp.2014.010.197.html

Swirl-inducing inlet for passive micromixers

Takuya Matsunaga and Koichi Nishino

RSC Advances 4 ( 2 ) 824 - 829 2013年11月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry 共著

T字チャネルにおける物質混合を促進する方法として、合流流路の入口部に単純な段差を設けることを考案し、その効果を数値解析手法（上記59）を用いて定量的に示した結果をまとめたもの。段差によって生じるSwirlが合流流路における対流混合を顕著に促進することを示した。

Semi-Lagrangian method for numerical analysis of fluid mixing in T-shaped micromixer

Takuya Matsunaga and Koichi Nishino

Journal of Chemical Engineering of Japan 46 ( 10 ) 699 - 708 2013年10月 [査読有り]

DOI Web of Science

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 Society of Chemical Engineers, Japan 共著

マイクロ流れにおける高Pe数流体の濃度拡散（物質移動）を対象とした数値解析手法（上記57）を改善した内容を報告したもの。分子拡散を合理的に考慮するため、非拡散粒子のラグラジアン追跡の中に分子拡散の効果をモデル化することを提案し、その効果をマイクロT字チャネルでの濃度拡散について検証した。

Numerical simulation of heat transfer coefficient and film-cooling performance influenced by the orientation of internal turbulence promoting ribs

Yukiko AGATA, Toshihiko TAKAHASHI, Eiji SAKAI, Koichi NISHINO

Journal of Thermal Science and Technology 8 ( 3 ) 488 - 503 2013年9月 [査読有り]

DOI Web of Science

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 of Mechanical Engineers and The Heat Transfer Society of Japan 共著

ガスタービン翼モデルの全面膜冷却における強制対流伝熱特性を数値解析（detached eddy simulation）で調べ、正味熱流束低減と正味表面温度低下を定量化することによって、乱流促進リブの傾斜方向の影響を客観的に判断できることを報告したもの。従来の翼面温度のみに着目した評価に比べて、正味熱流束低減を併せて考慮することの重要性を示した。

その他リンク： https://www.jstage.jst.go.jp/article/jtst/8/3/8_488/_article

Hydrothermal Wave Instability in a High-Aspect-Ratio Liquid Bridge of Pr > 200

Fumihiko Sato, Ichiro Ueno, Hiroshi Kawamura, Koichi Nishino, Satoshi Matsumoto, Mitsuru Ohnishi, M … 全著者表示

Microgravity Science and Technology 25 ( 1 ) 43 - 58 2013年2月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

西野が研究代表者を務めた液柱マランゴニ対流の宇宙実験（ニックネーム：MEIS）について、高アスペクト比液柱の高Ma数条件において、液柱表面を伝播するHTW（hydrothermal wave）の特性を明らかにした結果を報告したもの。時空間相関図、フーリエ解析、擬位相空間図を用いて特性を定量化した。

その他リンク： http://link.springer.com/article/10.1007%2Fs12217-012-9332-7#

Effect of Orientation of Internal Turbulence Promoting Ribs on Flow Characteristics for Film Cooling

Yukiko AGATA, Toshihiko TAKAHASHI, Eiji SAKAI, Koichi NISHINO

Journal of Thermal Science and Technology 8 ( 1 ) 15 - 27 2013年1月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

ガスタービン翼モデルの全面膜冷却における強制対流伝熱特性を数値解析（detached eddy simulation）で調べた結果をまとめたもの。乱流促進リブの傾斜方向によって、冷却孔からの吹き出し空気の速度分布が変化し、それが翼面上の伝熱特性に大きな影響を与えていることを明らかにした。

その他リンク： https://www.jstage.jst.go.jp/article/jtst/8/1/8_15/_article/-char/ja/

An approach for accurate simulation of liquid mixing in a T-shaped micromixer

Takuya Matsunaga, Ho-Joon Lee and Koichi Nishino

Lab on a Chip 13 ( 8 ) 1515 - 1521 2013年1月 [査読有り]

DOI Web of Science PubMed

記述言語：英語掲載種別：研究論文（学術雑誌）共著

マイクロ流れにおける高Pe数流体の濃度拡散（物質移動）について、誤差となる数値拡散の影響を効率的に回避する計算方法を報告した論文。非拡散性の粒子をラグラジアン追跡し、その後に拡散性をモデル化して加味するという方法。マイクロT字チャネルにおける濃度拡散を妥当に数値計算できることを示した。

その他リンク： http://pubs.rsc.org/en/content/articlelanding/2013/LC/c3lc41009a#!divAbstract

Stereo-PIV measurement of turbulence characteristics in a flow mixer

Shekhar Chandra, Nishino Koichi, Yamane Yoshiyuki, Huang Jian

Journal of Visualization 15 ( 4 ) 293 - 308 2012年11月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Three-component, turbulent flow measurements are performed using stereo PIV technique, in a cylindrical, stirred, water-flow mixer, with commercially available HR-100 as the impeller, which has three identical blades, separated by 120° with each other. The flow is analyzed at twelve axisymmetric, vertical planes, with the regular angular interval of 10°, so that the 12 planes cover the whole 120° separation between any two of the impeller blades. The results show that the turbulence mixing below the impeller is much higher than that above it, as the bulk fluid motion convects down the turbulence produced at the blade–water interfaces. Moreover, vortices with high level of turbulence, overwhelmingly dominated by the tangential velocity fluctuations, are created near the tips of the blades and convected downward, with their turbulence gradually dissipating with time. When these vortices are connected throughout the domain, they constitute three disconnected, helical arcs, each of which is connected to the tip of a blade and extends downward in the opposite direction to the rotation of the impeller. The arcs rotate with the same angular velocity of the impeller. The mean velocity and turbulence statistics of the flow are discussed at each of the alternate measurement planes.

3-D PTV measurement of Marangoni convection in liquid bridge in space experiment

Yano Taishi, Nishino Koichi, Kawamura Hiroshi, Ueno Ichiro, Matsumoto Satoshi, Ohnishi Mitsuru, Sak … 全著者表示

Experiments in Fluids 53 ( 1 ) 9 - 20 2012年7月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Microgravity experiments have been conducted on the International Space Station in order to clarify the transition processes of the Marangoni convection in liquid bridges of high Prandtl number fluid. The use of microgravity allows us to generate large liquid bridges, 30 mm in diameter and up to 60 mm in length. Three-dimensional particle tracking velocimetry (3-D PTV) is used to reveal complex flow patterns that appear after the transition of the flow field to oscillatory states. It is found that a standing-wave oscillation having an azimuthal mode number equal to one appears in the long liquid bridges. For the liquid bridge 45 mm in length, the oscillation of the flow field is observed in a meridional plane of the liquid bridge, and the flow field exhibits the presence of multiple vortical structures traveling from the heated disk toward the cooled disk. Such flow behaviors are shown to be associated with the propagation of surface temperature fluctuations visualized with an IR camera. These results indicate that the oscillation of the flow and temperature field is due to the propagation of the hydrothermal waves. Their characteristics are discussed in comparison with some previous results with long liquid bridges. It is shown that the axial wavelength of the hydrothermal wave observed presently is comparable to the length of the liquid bridge and that this result disagrees with the previous linear stability analysis for an infinitely long liquid bridge.

Measurements of gas/oil free surface deformation caused by parallel gas flow

Matsunaga T., Mialdun A., Nishino K., Shevtsova V.

Physics of Fluids 24 ( 6 ) 062101 2012年6月 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Flow-induced dynamic free-surface deformations are experimentally studied in a confined liquid volume of 5cSt silicone oil (Prandtl number Pr = 68). The geometry of the problem is a liquid column concentrically surrounded by an annular gas channel. A gas stream entering the duct from the top or bottom entrains the motionless liquid. The dynamic deformation of the gas–liquid interface is caused by a steady axisymmetric shear-driven flow. The experiments are performed in normal gravity conditions and the static deformation of a liquid bridge interface is unavoidable. The magnitude and shape of the dynamic surface deformation are analyzed using optical measurements with a comprehensive treatment of the images. The deviation of the free surface shape from the corresponding equilibrium profile is determined with an uncertainty of about 0.1 μm. The order of magnitude of the interface deformation is proportional to the capillary number, which is defined as the ratio of the viscous force per unit area to the capillary pressure. The study is performed for a large range of volumes and aspect ratios as well as for different gas velocities. As a general trend, the dynamic deformation grows with the gas velocity, which plays the role of a driving force, but a linear dependence is not observed for all volume ratios, despite the small Reynolds numbers, 280 < Reg < 560. The dynamic deformation displays a strong dependence on the liquid volume ratio and the direction of the gas stream parallel to the interface. When the gas flow is directed against gravity, the largest interface deformations are observed at the smallest volumes among the analyzed ones. In contrast, when the gas stream is aligned with gravity, then the deformations decrease with a decrease in the volume ratio, at a certain value attaining zero (vanishing) and then changing sign.

Report on Microgravity Experiments of Marangoni Convection Aboard International Space Station

Kawamura Hiroshi, Nishino Koichi, Matsumoto Satoshi, Ueno Ichiro

Journal of Heat Transfer 134 ( 3 ) 031005 2012年1月 [査読有り]

DOI Web of Science

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 Americal Society for Mechanical Engineers 共著

This paper reports some important results obtained from a series of microgravity experiments on the Marangoni convection that takes place in liquid bridges. This project, called Marangoni Experiment in Space (MEIS), started from August 22, 2008 as the first science experiment on the Japanese Experimental Module “KIBO” at the ISS. Two series of experiments, MEIS-1 and 2, were conducted in 2008 and 2009, respectively. The experimental methods used are explained in some detail. The maximum size of the liquid bridge that could be realized during these experiments was 30 mm in diameter and 60 mm in length, giving an aspect ratio of 2.0. The results are obtained for a wide range of aspect ratios of the liquid bridges, including the values that cannot be reached in 1 g experiments, and therefore, they provide indispensable amount of data for the study of instability mechanisms of the Marangoni convection.

Micro-PIV measurement and CFD analysis of a thin liquid flow between rotating and stationary disks

Lee, HJ., Nishino, K.

Journal of Visualization 14 249 - 258 2011年8月 [査読有り]

DOI Web of Science

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-Verlag 共著

A strongly sheared flow in a thin liquid layer between rotating and stationary disks is studied experimentally and numerically to clarify the characteristics of the flow in rotation-shearing chemical reactors. The disk diameter is 10 mm and the separation between the disks is 500 μm. The rotational speeds that are examined are 300, 500 and 700 rpm. The micro-PIV technique is used to measure the velocity in the liquid layer. A commercial CFD software is also used to obtain the results for the comparison and validation purposes. The overall velocity distributions revealed by the micro-PIV measurement are in good agreement with the CFD results. Both results show some interesting characteristics of the flow field, including the presence of a secondary flow and its influence on the tangential velocity profiles. The near-wall measurement in the micro-PIV technique is appreciably improved by the use of a simple digital, high-pass filtering technique that is applied to the acquired particle images. It is found that the flow characteristics in the thin liquid layer can be evaluated efficiently if the micro-PIV technique is used together with the high-pass filtering technique that is examined here.

その他リンク： https://link.springer.com/article/10.1007/s12650-011-0082-1

Heat Induced Separation in Upward Impinging Jet Flows Experimental Verification and Underlying Mechanism

Shekhar Chandra, Nishino Koichi

JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 6 ( 1 ) 93 - 110 2011年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Space experiment on the instability of Marangoni convection in large liquid bridge - MEIS-4: effect of Prandtl number -

T Yano, K Nishino, H Kawamura, I Ueno, S Matsumoto, M Ohnishi, M Sakurai

Journal ofPhysics:ConferenceSeries 327 ( 012029 ) 1 - 7 2011年 [査読有り]

DOI

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

Microgravity experiments on the thermocapillary convection in liquid bridge, called Marangoni Experiment in Space (MEIS), are carried out in "KIBO" of ISS. Three series of experiments, MEIS-1, 2, and 4, have been conducted so far. This paper reports the results obtained from MEIS-4, in which 20cSt silicone oil (Pr = 207) is used to generate large liquid bridges. They are suspended between coaxial disks that are 50mm in diameter, with their maximum length equal to 62.5mm. MEIS-4 aims at (1) determining the critical temperature difference for the onset of oscillatory flow; (2) realizing high Marangoni number conditions for high Pr fluid; (3) clarifying the effects of volume ratio, heating rate, hysteresis, and cooled disk temperature; and (4) observing whether the hydrothermal wave with azimuthal mode number m = 0 appears or not. The main results are presented and compared with those obtained in MEIS-1 and 2, which utilized liquid bridges of 5cSt silicone oil (Pr = 67).

その他リンク： https://iopscience.iop.org/article/10.1088/1742-6596/327/1/012029

Onset of Hydrothermal Instability in Liquid Bridge. Experimental Benchmark

V. Shevtsova, A. Mialdun, H. Kawamura, I. Ueno, K. Nishino, M. Lappa

FDMP: Fluid Dynamics & Materials Processing 7 ( 1 ) 1 - 27 2011年 [査読有り]

DOI

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Tech Science Press 単著

The experimental results from nine benchmark test cases conducted by five different groups are presented. The goal of this study is to build an experimental database for validation of numerical models in liquid bridge geometry. The need arises as comparison of numerical results with a single experiment can lead to a large discrepancy due to specific experimental conditions. Perfectly conducting rigid walls and, especially, idealized boundary conditions at the free surface employed in numerical studies are not always realized in experiments. The experimental benchmark has emphasized strong sensitivity of the threshold of instability to the liquid bridge shape. A clear distinction should be made between results belonging to the different disturbance patterns, i.e. different wave numbers. The results of benchmark contributors are in a satisfactory agreement when they are associated with the stability branch with an identical wave number. In this case the discrepancy of the results for determination of the critical parameters is about +-15%-18% and they can be used for the validation of numerical models.

その他リンク： https://www.researchgate.net/profile/Marcello_Lappa/publication/235407848_Onset_of_Hydrothermal_Instability_in_Liquid_Bridge_Experimental_Benchmark/links/00463516c2518b69b0000000/Onset-of-Hydrothermal-Instability-in-Liquid-Bridge-Experimental-Benchmark.pdf

3-D Flow Measurement of Oscillatory Thermocapillary Convection in Liquid Bridge in MEIS

Taishi YANO, Koichi NISHINO, Hiroshi KAWAMURA, Ichiro UENO, Satoshi MATSUMOTO, Mitsuru OHNISHI, Shi … 全著者表示

International Journal of Microgravity Science and Application 28 ( 2 ) S126 - S131 2011年 [査読有り]

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 of Microgravity Application 共著

Marangoni Experiment in Space (MEIS) has been conducted in the International Space Station (ISS) in order to clarify the transition processes of thermocapillary convection in liquid bridges. The use of microgravity allows us to generate long liquid bridges, 30mm in diameter and up to 60mm in length. Several flow visualization techniques have been applied to those large liquid bridges. 3-D PTV is used to reveal highly three-dimensional flow patterns that appear after the transition. Three CCD cameras are used to observe the motions of the tracer particles from different view angles through the transparent heated disk made of sapphire. Particle images are recorded in the HDD recording system in ISS and they are downloaded to the ground for data analysis. A conventional 3-D PTV technique and a newly-developed multi-frame particle tracking method are combined to obtain the results that can help better understanding of oscillatory 3-D flow fields in the liquid bridges. It is shown that the flow pattern changes from a 2-D axisymmetric steady flow to an oscillatory 3-D non-axisymmetric flow under the supercritical conditions.

その他リンク： http://www.jasma.info/wp-content/uploads/past/assets/images/jornal/28-2/2011_p126.pdf

Numerical Study of Steady Thermocapillary Convection in a Cylindrical Half-Floating-Zone

Shaligram Tiwari, Koichi Nishino

International Journal of Fluid Mechanics Research 37 ( 6 ) 506 - 529 2010年 [査読有り] [招待有り]

DOI

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

Numerical investigations are carried out to study the steady thermocapillary flow in a half-floating-zone, suspended vertically between two differentially heated disks of circular cross-section. The surface tension driven flow inside the floating zone gets strongly influenced by the flow conditions of the surrounding gas. Computations are carried out over a wide range of Marangoni numbers (Ma) to investigate the flow behavior in the floating zone and surrounding gas and heat transfer at the liquid-gas interface. A comparison of flow and temperature fields within the liquid bridge and the surrounding air under normal and microgravity conditions has been presented. Heating of the confined and unconfined ambient gas is observed to influence the radial and axial temperature gradients at the liquid-gas interface and within the liquid bridge which in turn affects the nature of thermocapillary flow.

その他リンク： http://www.dl.begellhouse.com/journals/71cb29ca5b40f8f8,34053a9e69b46003,1759f48e00edb585.html

Conjugate Heat Transfer Computation for Evaluation of Single-Blow Method for Compact Fin-Tube Heat Exchangers

Song Gil-Dal, Nishino Koichi

JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 3 ( 2 ) 219 - 233 2008年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Numerical Investigation for Net Enhancement in Thermal-Hydraulic Performance of Compact Fin-Tube Heat Exchangers with Vortex Generators

Song Gil-Dal, Nishino Koichi

JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 3 ( 2 ) 368 - 380 2008年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Simultaneous Heat Transfer Enhancement and Pressure Loss Reduction for Finned-Tube Bundles with the First and Two Transverse Rows of Built-in Winglets

K.-M. Kwak

International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics 29 625 - 632 2005年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

3-D PTV Measurement of Oscillatory Thermocapillary Convection in Half-Zone Liquid Bridge

M. Nishimura, I. Ueno and H. Kawamura

Experiments in Fluids 38 ( 3 ) 285 - 290 2004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）共著

Measurement of Dynamic Surface Deformation of Liquid Bridge with Thermocapillary Convection by Using Temporal Speckle Pattern Interferometry

Shin-ichi Yoda

Journal of The Japan Society of Microgravity Application 21 ( 4 ) 267 - 275 2004年 [査読有り]

記述言語：英語掲載種別：研究論文（学術雑誌）共著

PIV Measurement of Internal Flow Characteristics of Very Low Specific Speed Semi-open Impeller

Y.-D. Choi, J. Kurokawa, J. Matsui

Experiments in Fluids 37 617 - 630 2004年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

Temporal Speckle Pattern Interferometry for Measuring Micron-order Surface Motion of Liquid Bridge

Xinbo Li, Shin-ichi Yoda

Measurement Science and Technology 15 2284 - 2294 2004年 [査読有り]

DOI Web of Science

記述言語：英語掲載種別：研究論文（学術雑誌）共著

混相流計測法

森北出版 130 - 133, 193-197, 257-262 2003年

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Heat Transfer and Folw Characteristics of Fin-Tube Bundles with and without Vortex Generators

Experiments in Fluids 33 696 - 702 2002年

記述言語：英語掲載種別：研究論文（その他学術会議資料等）

PIVハンドブック

森北出版 165 - 211, 212-220, 266-267, 282-283, 308-312 2002年

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

マイクロ流れの速度場計測

日本流体力学会会誌「ながれ」 20 ( 2 ) 83 - 91 2001年

記述言語：日本語掲載種別：研究論文（その他学術会議資料等）

Stereo Imaging for Simultaneous Measurement of Size and Velocity of Particles in Dispersed Two-Phase Flow

Measurement Science and Technology 11 633 - 645 2000年

DOI Web of Science

記述言語：英語掲載種別：研究論文（その他学術会議資料等）単著

PIV Measurement of Internal Structure of Diesel Fuel Spray

Experiments in Fluids 29 ( 7 ) S211 - S219 2000年

DOI Web of Science

記述言語：英語掲載種別：研究論文（その他学術会議資料等）単著

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