六附属旋转小圆柱对主圆柱绕流特性的影响

Influence of six small rotating rods on flow characteristics of main cylinder

基于计算流体动力学方法,对雷诺数Re=200条件下,六附属旋转小圆柱与主圆柱体二维绕流进行了数值模拟。考虑来流攻角(θ=0°-60°)与附属圆柱旋转速率(α=0.0-2.0)两个关键参数对主圆柱体流体力系数,以及流场特性的影响,最后分析了附属圆柱临界转速与来流攻角之间的变化。结果表明:来流攻角和附属圆柱旋转速率的变化对主圆柱体流体力系数、流场流动模态及其互扰效应的影响较大。随来流攻角的变化,主圆柱周围的流场流动模态会发生显著变化,静止与低速旋转状态下(α=0.0-1.0),主圆柱尾流形态呈多样性;而在高速旋转状态下(α=1.0-2.0),主圆柱尾流形态较为单一。此外,附属圆柱临界转速随来流攻角的增大呈现先增大后减小的变化趋势。

Based on the computational fluid dynamics method,the flow around the six small rotating rods and the main cylinder is numerically simulated at Re=200.The influence of two key parameters,the incidence angle(θ=0°-60°)and the rotation rate of the rod(α=0.0-2.0)on the fluid force coefficient,average pressure coefficient,and flow field characteristics of the main cylinder is considered.Further,the relation change between the critical speed of the rod and the incidence angle is analyzed.The results show that the changes in the incidence angle and the rotation rate of the rod have a greater impact on the flow characteristics of the main cylinder,the flow mode of the flow field and the mutual interference effect.With the changes of the incidence angle,the flow mode of the flow field around the main cylinder will change significantly.In the state of static and low-speed rotation(α=0.0-1.0),the wake morphology of the main cylinder is diverse,while in the state of high-speed rotation(α=1.0-2.0),the wake of the main cylinder is relatively simple singleness.In addition,the critical speed of the rod shows an overall trend of first increasing and then decreasing with the increase of the incidence angle.