圆柱绕流尾迹转捩电磁力控制研究  

Transition control of cylinder wake via Lorentz force

作　　者：黄亚冬 王智河 周本谋[3] Huang Ya-Dong;Wang Zhi-He;Zhou Ben-Mou(National Research Center of Pumps,Jiangsu University,Zhenjiang 212013,China;School of Physics,Nanjing University,Nanjing 210093,China;Science and Technology on Transient Physics Laboratory,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]江苏大学,国家水泵及系统工程技术研究中心,镇江212013 [2]南京大学,物理学院,南京210093 [3]南京理工大学,瞬态物理国家重点实验室,南京210094

出　　处：《物理学报》2022年第22期165-177,共13页Acta Physica Sinica

基　　金：KJW创新项目(批准号:NLG1221991210829)资助的课题。

摘　　要：圆柱绕流是典型的振荡器流动,扰动在空间固定位置随时间增长,诱导尾迹转捩,从而增大柱体振动与流场噪声.本文通过在圆柱迎流面、背流面以及全圆柱表面放置电磁激活板产生流向电磁力,调控二维基态流,降低尾迹中扰动增长率,实现转捩模态改变. Floquet稳定性分析发现,迎流面控制中转捩模态A和B的增长率变化较小,而背流面和全圆柱控制中两种模态的增长率均随电磁力控制参数的增大而减小.分析椭圆不稳定和双曲不稳定诱导的无黏增长率发现,迎流面控制中尾迹高无黏增长率与无控制时相似,而背流面和全圆柱控制中均随电磁力作用参数的增大而减小.三维直接数值模拟发现圆柱尾迹三维形态在背流面控制和全圆柱控制中由模态B转变为模态A,与Floquet稳定性分析结果吻合.此外,当圆柱尾迹形态发生变化后,背流面控制和全圆柱控制下圆柱所受的阻力分别降低了15.2%和14.4%.The flow around a cylinder is a typical flow acting as the oscillator, and the perturbations can grow with time at a fixed position. This phenomenon can induce the laminar-turbulent transition in the wake, thus increasing the vibrations of the cylinder as well as the noise in the flow system. There exist three control strategies, i.e. the streamwise Lorentz force from the electromagnetic actuator set on the windward surface named windward control, the leeward surface named leeward control, and the whole surface of cylinder named global control, which are adopted to modify the two-dimensional base flow, thereby reducing the growth rates of perturbations in the wake and changing the transition mode. According to the Floquet stability analysis, it is found that the growth rates of the transition modes A and B present small changes in the windward control,while the growth rates of the two modes decrease with the increase of the control number in the other two control cases. Comparing the inviscid growth rates induced by the elliptic instability and the hyperbolic instability with each other, it is observed that the high inviscid growth rate in the windward control can be similar to those without control, while the inviscid growth rates can decrease with the increase of control number in the other two control cases. Three-dimensional direct numerical simulations are performed to validate the control effects. The results shows that the three-dimensional shape of the wake is changed from mode B to mode A when the actuator is set on the leeward surface or the whole surface of the cylinder. This is consistent with the result from the Floquet stability analysis. In addition, the drag of the cylinder reduces 15.2% for the leeward control and 14.4% for the the global control.

关 键 词：圆柱尾迹 流向电磁力 转捩控制 流动稳定性 

分 类 号：O357.5[理学—流体力学]