电弧放电等离子体对超声速边界层影响的数值模拟

Numerical Simulation to the Effect of Arc Discharge Plasma Flow Control on Supersonic Boundary Layer

基于电弧放电等离子体热阻塞机理,对等离子体超声速流动控制过程进行了数值模拟,研究了等离子体对边界层的影响,分析了放电区大小、温度等对其作用效果的影响。结果显示:在高温等离子体放电区的上下游近区发生了边界层分离及漩涡运动;在放电区内有两种边界层,即高温等离子体与外界低温气流之间的温度边界层和气流与壁面之间的粘性边界层;放电区内形成漩涡运动的原因有两个,即内外压差和边界层分离;上游边界层的分离点y轴坐标随温度的增大而减小;增大来流速度,放电区上游分离点y轴坐标呈先增大后减小的趋势、放电区内漩涡运动加剧、下游近区边界层分离点y轴坐标减小。

The effect of arc discharge plasma on high-speed flow control based on the dominant thermal mechanism is numerically investigated, the effect of arc discharge plasma flow control on transsonic boundary layer is studied and effects of different geometrical configurations and different plasma temperatures on arc discharge plasma flow control are analyzed in detailed. The results show that boundary layer separation and the vortex flow will occur in the near region up and down the plasma. There are two kinds of boundary layer caused by plasma; the first kind of boundary layer is caused by temperature gradient and the second is caused by the viscosity between flow and the wall. The vortex flow is caused by the pressure differential between outside and inside of plasma locus and the viscosity between flow and the wall. The y coordinate of separation point will decrease with the plasma temperature, The y coordinate of separation point in the near region up the plasma will increase with the increase of flow velocity but it will decrease when the velocity keep on increase. The y coordination of separate point in the near region down the plasma will decrease as the flow velocity increases. And the vortex flow will speed up as the flow velocity increases.