Experimental Investigation of a Flapping Motion Downstream of a Backward Facing Step

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI:10.1115/FEDSM2018-83327

Zhuoyue Li, N. Gao

{"title":"Experimental Investigation of a Flapping Motion Downstream of a Backward Facing Step","authors":"Zhuoyue Li, N. Gao","doi":"10.1115/FEDSM2018-83327","DOIUrl":null,"url":null,"abstract":"The flow field downstream of a backward facing step with Reynolds numbers of 1050–3890 were studied using stereoscopic particle image velocimetry (PIV) with field-of-views perpendicular to the incoming flow. It was found that the separated shear layer underwent a flapping motion with a frequency fH/Uo ≲ 0.04, much smaller than the shedding frequency (fH/Uo ≈ 0.1) for Reynolds number larger than 2000. Here H is the step height and Uo is the freestream velocity. The low frequency flapping motion appeared to be two dimensional, i.e. the motion was in-phased in the spanwise direction. The cause of the flapping motion is still not clear.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"19 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1115/FEDSM2018-83327","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 1

Abstract

The flow field downstream of a backward facing step with Reynolds numbers of 1050–3890 were studied using stereoscopic particle image velocimetry (PIV) with field-of-views perpendicular to the incoming flow. It was found that the separated shear layer underwent a flapping motion with a frequency fH/Uo ≲ 0.04, much smaller than the shedding frequency (fH/Uo ≈ 0.1) for Reynolds number larger than 2000. Here H is the step height and Uo is the freestream velocity. The low frequency flapping motion appeared to be two dimensional, i.e. the motion was in-phased in the spanwise direction. The cause of the flapping motion is still not clear.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

后向台阶下扑动的实验研究

采用垂直于来流视场的立体粒子图像测速技术(PIV)研究了雷诺数为1050 ~ 3890的后台阶下游流场。结果表明，当雷诺数大于2000时，分离剪切层发生的扑动频率为fH/Uo≈0.04，远小于脱落频率(fH/Uo≈0.1)。这里H是台阶高度，Uo是自由流速度。低频扑动表现为二维运动，即在展幅方向上呈同相运动。扇动的原因尚不清楚。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl

自引率

0.00%

发文量