{"title":"Bubble Wake Visualization by using Photochromic Dye","authors":"T. Sanada, Minori Shirota, Tomoki Ono, Masaomi Watanabe","doi":"10.3154/TVSJ.27.47","DOIUrl":"https://doi.org/10.3154/TVSJ.27.47","url":null,"abstract":"ジグザグもしくはらせん運動を行う上昇気泡の後流について，実験的に調査した．単一の気泡をシリコンオイル中に発生させ，その後流をフォトクロミック染料を用いることで可視化した．気泡の挙動と後流は，高速度ビデオカメラを用いて同時にステレオ撮影した．その結果，気泡がらせん運動を開始する際には，ダブルスレッド型と思われる二本の渦構造が観察された．また気泡が形状振動を伴いながらジグザグ運動を行う際には，複数の馬蹄形の渦構造が観察された．","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121031339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-07-01DOI: 10.3154/jvs.27.supplement1_87
菖蒲 和晃, 舟木 治郎, 平田 滕哉
ABSTRACT Pulsating jets are very common and sometimes useful in industrial fields, due to some differences in basic characteristics from steady jets. In this research, the authors focuse upon the frequency effect of pulsation on a circular jet. Experiments are conducted at a Reynolds number of 5,000, Strouhal numbers of 0.13, 0.20 and 0.27, and a velocity-amplitude ratio of 0.5. Using olive-oil smoke, the authors visualise the flow near a nozzle exit, and get quantitative information by a PIV technique. Measurements on the entrainment flow rate give us another specific flow information, on which we discuss the frequency effect.
{"title":"Time Series of Consecutive PIV Analyses on a Pulsating Jet","authors":"菖蒲 和晃, 舟木 治郎, 平田 滕哉","doi":"10.3154/jvs.27.supplement1_87","DOIUrl":"https://doi.org/10.3154/jvs.27.supplement1_87","url":null,"abstract":"ABSTRACT Pulsating jets are very common and sometimes useful in industrial fields, due to some differences in basic characteristics from steady jets. In this research, the authors focuse upon the frequency effect of pulsation on a circular jet. Experiments are conducted at a Reynolds number of 5,000, Strouhal numbers of 0.13, 0.20 and 0.27, and a velocity-amplitude ratio of 0.5. Using olive-oil smoke, the authors visualise the flow near a nozzle exit, and get quantitative information by a PIV technique. Measurements on the entrainment flow rate give us another specific flow information, on which we discuss the frequency effect.","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"52 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133351815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of an Interactive Visualization System for the Taylor-Couette Flow","authors":"H. Furukawa, Yasuyuki Kobayashi, Takashi Watanabe, I. Nakamura","doi":"10.3154/tvsj.25.45","DOIUrl":"https://doi.org/10.3154/tvsj.25.45","url":null,"abstract":"3次元の可視化は流れの構造を理解するための重要な方法です．本研究では，低アスペクト比のテイラー・クエット流れにおいて，任意の複数受動粒子の動きを追跡することができる可視化システムの構築を目指す．対象とする2重円筒は有限長であり，内円筒が回転し，外円筒が静止している．上下端面は固定端面とする．用いる速度データは，流れが十分に発達し定常状態に落ち着いた時刻におけるデータを用いている．スタガード格子を用いて，3次元空間上で補間するアルゴリズムを開発し，粒子を追跡することに成功した．ユーザーは，追跡開始点，時間刻み幅等を可視化操作ウィンドウ上において変更することができる．流跡線の描画後やアニメーション中に，ユーザーはマウス操作をすることにより視点を変えることができる．","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121671117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Shimizu, H. Nakayama, T. Ito, Y. Tsuji, Y. Kukita
Large-scale streaming can occur near the interface between immiscible liquids when the liquids are excited vertically within a cylindrical enclosure. The most significant feature of this phenomenon is formation of an intermittent, but unidirectional, jet-like flow that leaves the center of the interface when an axisymmetric, fundamental-mode wave is exited on the interface. The jet induces a large-scale recirculating flow extending a few cylinder diameters away from the interface, a spatial scale considerably greater than the wavelength or amplitude of the interface waves, and having a time scale much greater than the excitation inter-val. The depth of the recirculation region increases with an increase in the wave amplitude. The recirculating flow is driven by a downward jet that forms below the center of the interface. The downward jet persists because a stagnation point forms below the interface each time when the center of interface is rising to form a crest.
{"title":"Large-Scale Streaming Caused by Forced Vertical, Cyclic Motion of Fluid-Fluid Interface: Interface Wave Profile and Overall Flow Behavior","authors":"J. Shimizu, H. Nakayama, T. Ito, Y. Tsuji, Y. Kukita","doi":"10.3154/TVSJ.24.9","DOIUrl":"https://doi.org/10.3154/TVSJ.24.9","url":null,"abstract":"Large-scale streaming can occur near the interface between immiscible liquids when the liquids are excited vertically within a cylindrical enclosure. The most significant feature of this phenomenon is formation of an intermittent, but unidirectional, jet-like flow that leaves the center of the interface when an axisymmetric, fundamental-mode wave is exited on the interface. The jet induces a large-scale recirculating flow extending a few cylinder diameters away from the interface, a spatial scale considerably greater than the wavelength or amplitude of the interface waves, and having a time scale much greater than the excitation inter-val. The depth of the recirculation region increases with an increase in the wave amplitude. The recirculating flow is driven by a downward jet that forms below the center of the interface. The downward jet persists because a stagnation point forms below the interface each time when the center of interface is rising to form a crest.","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127269248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"直方体周り流れの PIV・LDA 計測","authors":"友和 野村, 経章 石間, 富夫 小保方","doi":"10.3154/TVSJ.23.31","DOIUrl":"https://doi.org/10.3154/TVSJ.23.31","url":null,"abstract":"本研究では，もっとも基本的な流れの一つである平板上に置かれた直方体周り(長さ65mm×幅58mm×高さ31mm)の流れを，PIV(particle image velocimetry)と二次元LDA(laser Doppler anemometer)を用いて測定した．本研究では主流平均流速は4.0m/s，相対乱れ強さ1.5%として実験を行った．両者の比較は，平均流速，乱れ強さ及びレイノルズ応力について行い，乱流特性や測定精度の相互検証を行った．また，LDA測定におけるカルマン渦のような低周波数の流速変動の影響，PIV測定での検査領域の大きさが測定結果に与える影響に関しても調べた．さらに，PIVにより得られる瞬時流速分布に対してレイノルズ分解，Galilean分解，渦度表示などを適用することで直方体周り流れの瞬時の渦構造を解析した．","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"875 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133765130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Matsumoto, Yoshitomo Shintani, M. Okada, Keizo Imahori, T. Ohnishi, I. Ishihara, M. Ozawa
{"title":"Flow Pattern in a Simulated Tube-Nested Combustor","authors":"R. Matsumoto, Yoshitomo Shintani, M. Okada, Keizo Imahori, T. Ohnishi, I. Ishihara, M. Ozawa","doi":"10.3154/TVSJ.22.15","DOIUrl":"https://doi.org/10.3154/TVSJ.22.15","url":null,"abstract":"","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121810228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Measurement accuracy of a fast-scanning X-ray CT, designed to measure the unsteady void fraction and the interface area in multi-phase flow, was evaluated with spherical and cylindrical acrylic phantoms of known dimensions. Limitations of the spatial resolution and the object velocity were examined from the velocity and dimensions of the phantoms, X-ray fan beam thickness, and the scanning speed. Measurement errors less than 5% can be achieved by appropriate selection of the threshold level in binary images for stationary objects. However, the errors exceed over 20% for spherical objects moving at 1.0m/s. Another phantom simulating a unit of slug bubble frequently seen in multi-phase flow was scanned with the fast X-ray CT and its profile was compared with the phantom's actual dimensions. The results showed the system's successfull capability to reproduce the cylindrical part, while a further improvement is required to resolve detailed interface structure at the rear end of the phantom moving at large velocities.
{"title":"Interface Measurement of Moving Objects by Using a Fast X-ray CT Scanner","authors":"M. Misawa, N. Takada, N. Ichikawa, M. Akai","doi":"10.3154/TVSJ.21.38","DOIUrl":"https://doi.org/10.3154/TVSJ.21.38","url":null,"abstract":"Measurement accuracy of a fast-scanning X-ray CT, designed to measure the unsteady void fraction and the interface area in multi-phase flow, was evaluated with spherical and cylindrical acrylic phantoms of known dimensions. Limitations of the spatial resolution and the object velocity were examined from the velocity and dimensions of the phantoms, X-ray fan beam thickness, and the scanning speed. Measurement errors less than 5% can be achieved by appropriate selection of the threshold level in binary images for stationary objects. However, the errors exceed over 20% for spherical objects moving at 1.0m/s. Another phantom simulating a unit of slug bubble frequently seen in multi-phase flow was scanned with the fast X-ray CT and its profile was compared with the phantom's actual dimensions. The results showed the system's successfull capability to reproduce the cylindrical part, while a further improvement is required to resolve detailed interface structure at the rear end of the phantom moving at large velocities.","PeriodicalId":226842,"journal":{"name":"Transaction of The Visualization Society of Japan","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117131925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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