An Investigation of the Wake Structure and Aerodynamic Characteristics of a Finite Circular Cylinder : Time-Averaged Wake Structures behind Circular Cylinders with Various Aspect Ratios
An Investigation of the Wake Structure and Aerodynamic Characteristics of a Finite Circular Cylinder : Time-Averaged Wake Structures behind Circular Cylinders with Various Aspect Ratios
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DOI：
10.1299/jsmeb.42.178
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发表时间：
1999-05
期刊：
影响因子：
--
通讯作者：
Shuji Tanaka;S. Murata
中科院分区：
文献类型：
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作者：
Shuji Tanaka;S. Murata
在雷诺数为3.7×10~4的情况下，计算了均匀流中长宽比为1.25~10的有限长圆柱体后的时均绕流场，并给出了长宽比对尾迹结构的影响。利用新研制的旋转偏航仪系统测量了圆柱下游直径为1~20的三维速度分布，讨论了有限长圆柱尾迹流场的细节。根据速度场计算了流线和涡线，并给出了尾迹结构，如尾迹中涡的形态及其形状随下游距离的变化。采用改进的半球形整流罩圆柱、圆管和平板，研究了圆柱顶部形状对尾流的影响。
Time-averaged flow fields behind finite circular cylinders with aspect ratios from 1.25 to 10 placed on a ground plate in a uniform flow were determined at a Reynolds number of 3.7×104 and influences of the aspect ratios on the wake structures have been presented. Three-dimensional velocity distributions from 1 to 20 diameters down-stream of the cylinders were measured using newly developed rotating yaw-meter system, from which the details of the wake flow fields behind the finite circular cylinders have been discussed. Streamlines and vortex lines were calculated from the velocity fields and the wake structures, such as the configurations of vortices in the wake and their changes in shapes with distance downstream, have been shown. Effects of the shapes of the cylinder top on the wake flows have been also examined using modified cylinders with a hemispherical fairing, circular pipes as well as flat plates.