亚临界雷诺数下电磁力控制圆柱体绕流场特性的脱体涡模拟  

The DES simulation for flow control around a circular cylinder using the electromagnetic force at a subcritical Reynolds number

作　　者：尹纪富[1] 李巍[1] 尤云祥[1] 胡天群[1] 

机构地区：[1]上海交通大学海洋工程国家重点实验室,上海200240

出　　处：《水动力学研究与进展（A辑）》2013年第4期495-506,共12页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(11272211);上海交通大学海洋工程国家重点实验室基金(GP010819)资助~~

摘　　要：该文利用Maxwell方程直接数值计算表面包覆电极与磁极圆柱体产生的电磁力分布,将其加入到动量方程中,采用脱体涡模拟(DES)方法,在亚临界雷诺数4(Re 5 10)下,对电磁力作用下圆柱体在弱电解质中的绕流场结构及其升阻力特性进行了数值模拟与分析。结果显示:电磁力可以增大圆柱体近壁面的流体动能,延缓流动分离,减弱绕流场的三维效应;同时电磁力还可以显著减小圆柱体阻力,抑制其阻力与升力脉动幅值,而且随着电磁力作用参数的增加,圆柱体平均阻力及其升力系数均方值均呈指数衰减特征。研究表明,在亚临界雷诺数下,电磁力可以有效地改善圆柱体绕流场结构,达到减小其阻力并抑制其升阻力脉动幅值之目的,因此是圆柱型结构一种有效流动的控制手段。The distribution of the electrqmagnetic force around a cylinder covered by electromagnetic actuators is obtained by solving Maxwell equation system, and then such a Lorentz force is added to the momentum equation of flow governing equation system. The Detached Eddy Simulation （DES） method is carried out to simulate and analyze the flow characteristics around a circular cylinder and its lift/drag characteristics in a weakly conductive fluid at the subcritical Reynolds number Re = 5~ 104. The results show that the electromagnetic force can increase the fluid kinetic energy near the cylinder walland delay flow separation around a circular cylinder, as well as weaken the flow three-dimensional effect. Moreover, the electromagnetic force can also significantly reduce the drag on the circular cylinder and inhibit the drag/lift fluctuation amplitudes, as well as the averaged drag and lift coefficients of the circular cylinder decay exponentially with the electromagnetic force increasing. The results imply that the electromagnetic force can effectively improve the flow structure around a circular cylinder to achieve the purpose of reducing the drag and inhibiting the drag/lift fluctuation amplitudes under subcritical Reynolds numbers, therefore the electromagnetic force is an effective method for flow control around the circular cylinder.

关 键 词：圆柱绕流 流动控制 电磁力 亚临界雷诺数 

分 类 号：O361[理学—流体力学]