化工学报2019，Vol.70Issue(7)：2520-2527,8.DOI:10.11949/0438-1157.20190048
射流卷吸边界层内相干结构的实验研究
Experimental studies on coherent structures in jet entrainment boundary layers
摘要
Abstract
On the axis-symmetric water jet test bench, the flow field structure in the entrainment boundary layer with the Reynolds number in the range of 1849－2509 was measured by the single-frame long exposure image method. It is found that engulfing and nibbling entrainment model occur intermittently with time, in the region of L=2D－3.5D streamwise and H=D－1.25D radial direction. It concludes from analyzing that the occurrence probability of engulfing increases with Reynolds number when Re>1915, the influence of Reynolds number on the occurrence probability of this structure decreases when Re>2311. The occurrence frequency of this coherent structure obtained by fast Fourier transform is between 10 Hz and 19 Hz. Special vortex structures were observed in the flow field during the occurrence of engulfing. The jet flow field are measured using moving single frame long exposure image method in Lagrangian coordinate system, and it is found that the vortex structure generally existed near the interface of turbulent regions and non-turbulent regions.关键词
单帧长曝光/运动单帧长曝光/卷吸边界层/射流/湍流与非湍流界面/涡结构Key words
single frame long exposure/move single frame long exposure/entrainment layers/jet/turbulent and non-turbulent interface/vortex structures分类
化学化工引用本文复制引用
ZHOU Lei,ZHOU Wu,GUO Yan’ang,CAI Xiaoshu..射流卷吸边界层内相干结构的实验研究[J].化工学报,2019,70(7):2520-2527,8.基金项目
国家自然科学基金项目(51327803,51576130) （51327803,51576130）
