壁面对并列双圆柱尾迹影响的实验研究  

Experimental study on the near-wake of two side-by-side circular cylinders influenced by a near-wall

作　　者：陈波[1] 李万平[1] 

机构地区：[1]华中科技大学土木工程与力学学院,武汉430074

出　　处：《水动力学研究与进展（A辑）》2011年第3期342-350,共9页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(10372033);西部灾害与环境力学教育部重点实验室开放基金

摘　　要：用压强传感器和PIV对近壁并列双圆柱尾迹频谱和涡结构进行了测量，来研究壁面对其尾迹特性的影响。实验在循环水槽内进行，雷诺数为1696（基于圆柱直径D），壁面边界层厚度为6．6D。两个重要的特征参数T／D和G／D（T为两圆柱中心间的距离，G为下圆柱与壁面间的距离）分别为：T／D=1．151和1．604；G／D=0-1．811。结果显示，对于T／D=1，151，当G／D为0．302～1．811时，两圆柱尾迹表现为base—bleed流动模式，随着G／D的增加，尾迹强度逐渐增强，尺寸逐渐减小。对于T／D=1．604，当G／D大于临界值时出现biased流动模式，随着G／D的增加，两圆柱的尾迹尺寸以及上圆柱的斯特鲁哈数St变化很小；当G／D小于临界值时，随着G／D的减小，两圆柱的尾迹尺寸都逐渐减小，上圆柱的St逐渐增加。To investigate the near-wake of two side-by-side circular cylinders influenced by a near-wall, a pressure sensor and particle image velocimetry （PIV） are used to measure the frequency spectrum and the vortex structure of the wake. The experiments were performed in a recirculation water channel, the Reynolds number based on the cylinder diameter （D） is 1696, the boundary layer thickness is 6.6D. The two significant variables T/D and G/D in the experiment are defined as： T/D = 1.151 and 1.604 （T is the cylinder center-to-center spacing）, and G/D = 0-1.811 （G is the spacing between the lower cylinder and the wall）. The results show that, for T/D = 1.151, when G/D ≥ 0.302, the wake behind the cylinders performs a base-bleed flowpattern, the wake region increases in strength and decreases in size when G/D increases from 0.302 to 1.811. For T/D = 1.604, when G/D is higher than a critical value, the wake behind the cylinders performs a biased flow pattern, the size of the wakes for both cylinders and the St for upper cylinder almost unchanged as G/D increasing; When G/D lower than the critical value, the size of the wake for both cylinders decreases and the St for the upper cylinder increases as G/D decreasing.

关 键 词：近壁 并列双圆柱 PIV 尾迹:涡脱落 

分 类 号：O351.3[理学—流体力学] TV135[理学—力学]