局部电弧丝状放电控制激波/边界层干扰的数值研究

Numerical Simulation of Localized Arc Filament Plasma Actuator for Shock Wave/Boundary Layer Interaction Control

关键词:  激波/边界层干扰  流场分离  局部电弧丝状放电激励  热阻塞  数值仿真

Key words:  Shock wave/boundary layer interaction  Flow separation  Localized arc filament plasma actuator  Thermal choking  Numerical simulation

摘要:

采用数值模拟的方法研究局部电弧丝状放电激励对激波/边界层干扰引起的气流分离的控制效果和机理。研究发现在干扰区上游和干扰区内进行电弧放电能够有效控制边界层的分离，且控制效果随着能量输入增大而增强，最大可使分离区减小40.6%，而在干扰区下游作用时对激波/边界层干扰基本没有影响。结合热阻塞效应，可得出电弧放电的作用机理是其产生的焦耳热在流场中造成局部流场阻塞，形成等离子体虚拟型面，在流场中诱导出微弱的斜激波和旋向相反的漩涡，增大了边界层内流体的动量，使其抵抗分离的能力增强，从而抑制了气流的分离。

Abstract:

The control effects and mechanism of localized arc filament plasma actuator for shock wave/boundary layer interaction control were numerically investigated. Results show that the arc discharge in or upstream the interaction region can effectively decrease separation and the maximum reduction of separation region is 40.6%，while arc discharge downstream the interaction region has no effects. Besides，the efficiency of control improves as the input energy increases. Based on the thermal choking effect，the control mechanism of arc discharge can be deduced that the Joule heat induced by discharge causes local thermal choke in the flow-field，which can be regarded as plasma virtual surface. The virtual surface induces an oblique shock and counter-rotating vortices in the flow-field. Thus the momentum of boundary layer and the resistance to separation increased，and the separation is depressed.