中等雷诺数圆柱尾流旋涡脱落的控制  

CONTROL OF VORTEX SHEDDING AT MODERATE REYNOLDS NUMBERS

作　　者：邵传平[1] 鄂学全[1] 魏庆鼎[2] 朱凤荣[2] 

机构地区：[1]中国科学院力学研究所,北京100080 [2]北京大学湍流研究国家重点实验室,北京100871

出　　处：《力学学报》2002年第4期609-615,共7页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(10172087)资助项目

摘　　要：介绍通过实验对圆柱尾流旋涡脱落进行抑制的方法及其结果.实验模型的展径比为38,实验的雷诺数范围为3×102～1.6×103.抑制方法是在圆柱（直径为D）表面沿展向每隔一定间距伸出一直径0.18D、长度为1.5D的小棒.实验结果表明,当棒间距小于3D,棒与来流夹角在30°～90°范围内,可有效抑制旋涡脱落.The suppression of vortex shedding from a circular cylinder has been studied exper-imentally in the Reynolds number range from 300 to 1600. The test was carried out in a water channel. The model cylinder was 1 cm in diameter, 38 cm in length. It was made of plexiglas and had a smooth surface. The cylinder was mounted on endplates at both ends and placed horizon-tally across the channel. Vortex shedding occurred to the cylinder in the Re number range tested. In order to suppress vortex shedding, a row of small rods of diameter 0.18cm and length 1.5cm were placed along the meridian of the cylinder. One end of each rod was perpendicularly connectedto the surface of the cylinder, and the other end exposed to the fluid. The rod distance and the angle of attack of the rods could be changed in order to adjust the suppression effect. The rod distance range tested was l/D = 1.0～3.0, and the range of angle of attack was β=0°～90°?The fluctuating velocities of the wake before and after suppression were measured by a Laser-Doppler Velometer at places 15～20 cm from the cylinder.Some typical fluctuating velocities in suppressed and unsuppressed wake and their power spec-tra have been, given in the paper. The distributions of the root-mean-square (r.m.s.) value of fluctuating velocities across the wake have also been given.To a fixed rod distance l/D = 1.0 and Reynolds number Re = 1600, when the angle of attack is in the zone 30°≤β<90° the method is very effective, vortex shedding is totally suppressed. When β is small, say, β= 0° the method is less effective, vortex shedding can not be suppressed. Compare to the maximum r.m.s. value of fluctuating velocity in unsuppressed wake, the values in the wakes when angle of attack β=0°,30°,45°,60°and 90° can be reduced to 77%, 55%, 51%, 48% and 61% respectively. The rod distance also influences the suppression effect. To a fixed angle of attack β= 30°?and Reynolds number Re = 1600, the maximum r.m.s. value of fluctuating velocity in rod distance l/D = 1,2,3 are

关 键 词：圆柱尾流 流动控制 旋涡脱落抑制 流致振动 中等雷诺数 

分 类 号：O357.52[理学—流体力学]