中文摘要：

引入一个窄条作为控制件，在Re=3．0×10^3～2．0×10^4范围内对圆柱尾流进行控制实验。窄条长度与柱体长度相同，厚度为柱体直径的0．015-0．025倍，宽度为柱体直径的0．18倍．窄条的两个长边与柱中心轴平行，而且三者共面．控制参数为窄条位置，可由间距（窄条到柱轴）比λ／（0．5D）和风向角卢（窄条面与来流的夹角）确定，采用流动显示和热线测量方法，对控制和未控制尾流的流动状态，平均速度分布和脉动速度情况，以及作用于柱体和控制件的总阻力进行了研究和比较．研究结果证明，当窄条位于柱体尾流中一定区域内时，可有效抑制柱体两侧的旋涡脱落．有效控制后的尾流湍流度也相应减小．在不同Re数下，找出了有效抑制旋涡脱落的窄条位置区域，并用动量积分估计了作用于柱体和窄条上的总阻力与光圆柱阻力的比值及其随风向角的变化．对λ／（0．5D）=2．9情况，得到了减阻的风向角区域（β=0°～40°与180°附近）以及最大减阻率32％．以上事实表明，在近尾流局部区域施加小的干扰，可改变较高Re数圆柱尾流的整体性质．

英文摘要：

A narrow strip has bee introduced as an element to control circular cylinder wakes at Reynolds numbers Re = 3.0 × 10^3 ～ 2.0 × 10^4. The strip is 0.18D （D is diameter of the cylinder） wide, 0.015D - 0.025D thick and as long as the cylinder. The long margins of the strip are parallel to and coplanar with the cylinder axis. The strip is fixed by a row of small rods distributed along a meridian and perpendicularly connected to the surface of the cylinder. The rods have been proven to have negligible influence on the flow. The control parameter is strip position, which can be determined by λ/（0.5D）- （unified） distance between the cylinder axis and the length-wise centerline of the strip, and β-angle of attack of the strip. The experiment was conducted in a low turbulence wind tunnel of.test section 2 m long, 60 cm wide and 60 cm high. Two circular cylinders of diameter D = 3 cm and 5 cm were tested respectively in the range of β = 0°～ 180° and λ/（0.5D） = 1.1 - 3.8. The overall information of the cylinder wake was visualized by smokewire technique and the detailed local information of fluctuating velocity was detected by a hot-wire anemometry at various points from Y/（0.5D） = -6.0 to 6.0 at a stream-wise station X/D = 12.5. Visualization pictures and power spectra of fluctuating velocities show that vortex shedding on both sides of the cylinder can be effectively suppressed if the strip is located in a certain zone in the near wake. The effective zones at Re = 6.3 × 10^3, 1.0×10^4 and 1.64×10^4 have been found out with accuracy 0.1 of A/O.5D and 2.5° of β. The zone enlarges slightly with the increase of Re in the range tested. Distributions of turbulence intensity for various/3 from 0° to 180°at λ/（0.5D） = 2.9 and Re = 1.64 - 10^4 have been measured. Compare with the case without control, the turbulence intensity on both sides of the wake is reduced when β is in the range of 0°～~50° or in the vicinity of 180°. However, in the range β = 60°～ 120°, an increa