Search Results 1-20 of 32392

  • Displacement speed statistics in an open turbulent jet spray flame

    Malkeson S.P. , Ahmed U. , Turquand d'Auzay C. , Pillai A.L. , Chakraborty N. , Kurose Ryoichi

    … This suggests that flow geometry in the absence of mean curvature might not be important in determining the mean behaviour of displacement speed and its components. … However, the modelling methodologies, which implicitly assume equality between the surface-weighted values of density-weighted displacement speed and local laminar burning velocity, might be rendered invalid for turbulent spray flames. …

    Fuel 286(1), 2021-02-15

    IR 

  • Numerical Study on the Route of Flame-Induced Thermoacoustic Instability in a Rijke Burner

    Dang Nannan , Zhang Jiazhong , Deguchi Yoshihiro

    … The simulation considers the reacting flow, flame dynamics, and radiation model to investigate the important physical processes. … A finite volume-based approach is used to simulate reacting flows under both laminar and turbulent flow conditions. …

    Applied Sciences 11(4), 1590, 2021-02-10

    IR 

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

    SANSICA Andrea , 橋本 敦 , 小池 俊輔 , 河内 俊憲 , SANSICA Andrea , HASHIMOTO Atsushi , KOIKE Shunsuke , KOCHI Toshinori

    流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2020オンライン (2020年9月28日-30日. 日本航空宇宙学会 : 宇宙航空研究開発機構(JAXA)オンライン会議)形態: カラー図版あり資料番号: AA2030013015レポート番号: JAXA-SP-20-008

    宇宙航空研究開発機構特別資料: 流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2020オンライン論文集 = JAXA Special Publication: Proceedings of Fluid Dynamics Conference / Aerospace Numerical Simulation Symposium 2020 Online (JAXA-SP-20-008), 109-118, 2021-02-08

    IR 

  • Modification of the Immersed Boundary Method for Improving Drag Prediction Accuracy of NASA-CRM  [in Japanese]

    菅谷 圭祐 , 今村 太郎 , SUGAYA Keisuke , IMAMURA Taro

    流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2020オンライン (2020年9月28日-30日. 日本航空宇宙学会 : 宇宙航空研究開発機構(JAXA)オンライン会議)形態: カラー図版あり資料番号: AA2030013020レポート番号: JAXA-SP-20-008

    宇宙航空研究開発機構特別資料: 流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2020オンライン論文集 = JAXA Special Publication: Proceedings of Fluid Dynamics Conference / Aerospace Numerical Simulation Symposium 2020 Online (JAXA-SP-20-008), 149-155, 2021-02-08

    IR 

  • Reciprocating propagation of premixed flame using time-variable-angle swirl vanes

    KOMIYAMA Masaharu , KUMAZAKI Takafumi , NISHIDA Satoshi

    … In this research, we developed time-variable-angle swirl vanes which had 56 mm of the inner diameter, 70 mm of the outer diameter and consisted of 36 vanes, each vane was directly connected to a stepping motor, and the swirl intensity could be changed periodically by keeping the constant air ratio and flow rate. …

    Journal of Thermal Science and Technology 16(2), JTST0022-JTST0022, 2021

    J-STAGE 

  • Droplet size decrease rate of secondary breakup in diesel fuel sprays

    SAITO Manabu , KOMADA Keisuke , SAKAGUCHI Daisaku , UEKI Hironobu

    … The velocity and size of the spray droplets were measured using a laser 2-focus velocimeter (L2F). … The velocity of small droplets that follow the flow was taken as the air velocity. … The Weber number was evaluated using the velocity of the droplets relative to air as the representative velocity. …

    Journal of Thermal Science and Technology 16(2), JTST0023-JTST0023, 2021

    J-STAGE 

  • Observation of droplet/liquid film impingement between different kinds of liquid simulating fuel spray collision on engine cylinder wall  [in Japanese]

    OKAMOTO Shinya , KAWASHIMA Hisanobu , UCHIDA Ryo , TANAKA Daisuke , ISHIMA Tsuneaki

    … In this experiment, a rectangular flow section is used as an example of collision between different liquids in a port injection engine. … The experimental results are well organized using Weber number calculated by using vertical velocity. … In the case of different kinds of liquids droplet-film impingement, the phenomenon can be categorized by modified Laplace number and Weber number based on the vertical velocity component of droplet velocity.</p> …

    Transactions of the JSME (in Japanese), 2021

    J-STAGE 

  • Influence of the aspect ratio of the sheet for an electric generator utilizing the rotation of a flapping sheet

    YAMANO Akio , IJIMA Hiroshi , SHINTANI Atsuhiko , NAKAGAWA Chihiro , ITO Tomohiro

    … Flutter-mills exhibit complex power generation performance characteristics that are highly dependent on the specifications of the flexible sheet and the inlet flow velocity. …

    Mechanical Engineering Journal 8(1), 20-00459-20-00459, 2021

    J-STAGE 

  • Estimation of flow around a cylinder in a duct based on plane measurement by four-dimensional variational approach  [in Japanese]

    HOSOYA Taichi , KAMETANI Yukinori , OSAWA Takayuki , TSUKAHARA Takahiro , HASEGAWA Yosuke

    <p>本研究では，円柱を含むダクト内の空間発達流に対して4次元変分法を適用し，円柱下流の2次元面内における限られた計測データに基づき，円柱周りの非定常三次元流れの再現を試みた．初期場と流体内部に仮定した体積力を制御変数として，推定値と計測値の誤差を最小化するように，上記の制御変数の最適化を行った．推定された流れ場は，計測領域を含む2次元面内においては，計測領域の外側においても正解場を精 …

    SEISAN KENKYU 73(1), 77-81, 2021

    J-STAGE 

  • Prediction of turbulent helicity and evaluation of Reynolds stress in the Ekman boundary layer  [in Japanese]

    KOYAMA Shoji

    <p>流体工学で用いられる典型的な乱流モデルである<i>k － ε</i><sub> </sub>モデルは，平均量を算出するに際し渦粘性係数を乱流エネルギー<i>k</i><sub> </sub>とその散逸率<i> ε</i><sub> </sub& …

    SEISAN KENKYU 73(1), 23-28, 2021

    J-STAGE 

  • CFD SIMULATIONS ON DISPERSION OF HIGH-TEMPERATURE EXHAUST GAS AROUND AN ISOLATED BUILIDING MODEL

    LIN Chao , OOKA Ryozo , KIKUMOTO Hideki , SATO Taiki , ARAI Maiko

    <p>非常用発電機の増加に伴い，建物周辺で高温高浮力な排気ガスの拡散が懸念されている．本稿では，定常レイノルズ平均ナビアストークス（RANS）モデルとラージエディシミュレーション（LES）を用い，建物後流から放出された高浮力ガスの拡散を予測し，風洞実験の結果で検証した．RANSモデルは平均速度を予測できたが，乱流運動エネルギーを過小評価した．LESは平均速度と乱流運動エネルギーを予測で …

    SEISAN KENKYU 73(1), 37-46, 2021

    J-STAGE 

  • Diffusion and Sinking of Organic Matter Load of Silver Salmon Farming in Miho Bay  [in Japanese]

    DONG Shuchuang , ZHOU Jinxin , LI Qiao , YOSHIDA Takero , KITAZAWA Daisuke

    <p>本報では前報に引き続き，ギンザケ養殖が周辺の環境に及ぼす影響を調べるために，流れ場・生態系結合モデルに養殖施設の抵抗とギンザケ養殖負荷モデルを組み込んで養殖場周辺の海水流況の数値シミュレーションを実施するとともに，残餌と糞の拡散と沈降特性を調べた．その結果，養殖生簀は周辺海域の流れに影響を及ぼすことが確認された．生簀直下の残餌と糞の負荷が最も多かった．また，残餌と糞の周辺海域への …

    SEISAN KENKYU 73(1), 51-56, 2021

    J-STAGE 

  • Dynamic modelling for the wake flow behind a square prism building model based on POD modes  [in Japanese]

    ZHANG Bingchao , OOKA Ryozo , KIKUMOTO Hideki

    <p>本研究では，角柱建物モデルの後流にあるカルマン渦放出の動的システムの識別を行った．まず，瞬時風速データに対して固有直交分解を実行し，振幅2 乗コヒーレンスを用いてモード間の位相整合性を検出した．4 つの最もエネルギーの高いモードにおいて，モード2 は流入変動風によって制御され，モード1，3，4 は，建物の後流で放出される主な渦を示すことが分かった．次に，3 次多項式回帰モデルを用 …

    SEISAN KENKYU 73(1), 57-63, 2021

    J-STAGE 

  • Computational Fluid Dynamics Analysis of Blood Flow Changes during the Growth of Saccular Abdominal Aortic Aneurysm  [in Japanese]

    Murakami Masanori , Jiang Fei , Kageyama Nobuyasu , Chen Xian

    <p>囊状腹部大動脈瘤の成長過程における数値流体力学解析を行った。CT画像を用い3次元形状モデルを作成。汎用熱流体解析ソフトウェアを用い壁面せん断応力，平均流速，平均圧力，エネルギー損失，圧力損失係数を計算した。瘤拡大に伴い平均流速は低下，壁面せん断応力，平均圧力，エネルギー損失，圧力損失係数は上昇した。壁面せん断応力は瘤径の小さい時点から上昇しており，動脈瘤の発生，成長に関与している …

    The Journal of Japanese College of Angiology 61(2), 3-10, 2021

    J-STAGE 

  • Effects of pressure and heat loss on the unstable motion of cellular-flame fronts caused by intrinsic instability in hydrogen-air lean premixed flames

    KADOWAKI Satoshi , Aung Thwe Thwe , FURUYAMA Taisei , KAWATA Kazumasa , KATSUMI Toshiyuki , KOBAYASHI Hideaki

    … Two-dimensional unsteady reactive flow was treated, and the compressibility, viscosity, heat conduction, molecular diffusion and heat loss were taken into account. … As the heat loss became larger, the former decreased and the latter narrowed, which were due mainly to the decrease of burning velocity. … The burning velocity of a cellular flame normalized by that of a planar flame increased as the pressure became higher and the heat loss became larger. …

    Journal of Thermal Science and Technology 16(2), JTST0021-JTST0021, 2021

    J-STAGE 

  • Meandering airflows beneath the underbody of a train model including bogie (LES of large-scale flow structure around real-shaped train model)  [in Japanese]

    NAKADE Koji , IDO Atsushi , KAJISHIMA Takeo

    … The shape of the underbody affects the flow. … Our experimental results qualitatively reproduced the power spectra of lateral velocity fluctuations in the underbody obtained using a 1:8.4-scale train model on a moving belt in a wind tunnel. … Results on the effects of various bogie shapes suggested that the meandering flow was primarily affected by the time-averaged profile of streamwise velocity. …

    Transactions of the JSME (in Japanese), 2021

    J-STAGE 

  • Study of the Cavitation Phenomenon Inside Roller Vane Pump

    Zhang Bin , Zhao Chun-xiao , Hong Hao-cen , Bai Da-peng , Yang Hua-yong

    … The computational fluid dynamics simulation method (CFD) based on dynamic meshing technique and user defined function (UDF) is applied to calculate flow dynamics and multi-phase flow characteristics, especially the flows inside the fluid film between the stator and valve plate. … The negative pressure region near the relief groove has an extreme low pressure at 0.08 MPa, and the maximum flow velocity is 99.3 m/s. …

    International Journal of Fluid Machinery and Systems 14(1), 42-51, 2021

    J-STAGE 

  • Bolus Inflow Detection Method by Ultrasound Video Processing for Evaluation of Swallowing

    Matsuzaki Takato , Suzuki Yutaka , Tanimoto Morimasa , Masuyama Keisuke , Osano Masashi , Sakata Osamu , Morisawa Masayuki

    … Moreover, we could distinguish the change caused by the inflow from the change caused by the elevation of the esophageal wall using the velocity results obtained by optical flow estimation in the anterior esophageal wall region. … Furthermore, an accuracy sufficient for estimation of the velocity of the bolus was achieved.</p> …

    Advanced Biomedical Engineering 10(0), 18-25, 2021

    J-STAGE 

  • Development of circular cylinder blade wind turbine driven by longitudinal vortex  [in Japanese]

    SAKAMOTO Kasumi , UDAKA Keita , HEMSUWAN Withun , TAKAHASHI Tsutomu

    … In this study, the flow-visualization by the smoke-wind tunnel confirms the generation of the longitudinal vortex that was predicted by the numerical analysis. … The steady lift force acting on the circular cylinder blade was measured and the relationship with the relative attack angle which is determined by the mainstream flow velocity and the moving velocity of the cylinder blade in crossflow direction was examined. …

    Transactions of the JSME (in Japanese), 2021

    J-STAGE 

  • Characterization of Cardiac- and Respiratory-driven Cerebrospinal Fluid Motions Using a Correlation Mapping Technique Based on Asynchronous Two-dimensional Phase Contrast MR Imaging

    Yatsushiro Satoshi , Sunohara Saeko , Tokushima Tetsuya , Takizawa Ken , Matsumae Mitsunori , Atsumi Hideki , Horie Tomohiko , Kajihara Nao , Kuroda Kagayaki

    … <p>Purpose: The cardiac- and respiratory-driven components of cerebrospinal fluid (CSF) motion characteristics and bulk flow are not yet completely understood. …

    Magnetic Resonance in Medical Sciences, 2021

    J-STAGE 

Page Top