化工学报2019，Vol.70Issue(4)：1349-1357,9.DOI:10.11949/j.issn.0438⁃1157.20180836
三维凹壁面切向射流流动特性分析
Flow characteristics of three-dimensional concave-wall jet
摘要
Abstract
To improve the mechanical separation efficiency of the heterogeneous material, a semi-circular cross-section tangential inlet is arranged in the vertical cylindrical separator to form a three-dimensional concave-wall jet. The concave-wall jet flow characteristics are studied by tracer concentration experiment and large eddy simulation. The aim is to reveal the three-dimensional concave-wall jet flow mechanism. The concentration field spread is evaluated along the streamwise and spanwise flow. The results show that the half-value width of the tracer concentration increases with the increase of the inlet Reynolds number. The streamwise spread ratio is in the range of 0.019—0.033 and the spanwise spread ratio is in the range of 0.079—0.161. Under the action of centrifugal force, the concentration half-value width shrinks to 2/3 of the jet width within the scope of 60° in the inlet circumferential direction. There are several streamwise vortices developed from the inner surface of the cylinder, however no vortex along spanwise flow is found. The peak values of tangential velocity half-value width and the vorticity boundary locates at the center of the streamwise vortex. There is not obvious fluctuation in spanwise direction. Secondary flow vortex is not found in the range of 180°in the inlet circumferential direction. The reason is that the ratio of the tangential velocity half-value width to the cylindrical radius is less than 0.1 along streamwise flow. Thus the forming condition of the secondary flow that caused by centrifugal instability is not reached. The concave wall tangential jet effectively reduces the disturbance of the main fluid in the stratifier by the vortex.关键词
凹壁面切向射流/涡旋/大涡模拟/示踪剂浓度/射流扩展Key words
concave-wall jet/vortex/large eddy simulation/tracer concentration/jet spread分类
数理科学引用本文复制引用
张静,周圆圆,龚斌,李雅侠,刘海良,吴剑华..三维凹壁面切向射流流动特性分析[J].化工学报,2019,70(4):1349-1357,9.基金项目
国家自然科学基金项目(51606132) （51606132）
天津市自然科学基金项目(16JCQNJC06400) （16JCQNJC06400）
