两道同侧扫掠激波作用下形成的三维平板边界层

Three-dimensional flat-plate boundary layers generated by two swept shock waves of the same side

为探索一种减弱扫掠激波/边界层干扰强度的侧压方式,采用数值计算方法研究两道同侧扫掠激波作用下形成的三维平板边界层。对三维边界层的流动机理进行研究,并与相同气流偏转角的一道扫掠激波作用下形成的三维边界层进行定量比较。研究表明,存在两道同侧扫掠激波时,第一道扫掠激波使侧壁附近边界层变薄,进而使第二道扫掠激波与再附形成的边界层的相互作用减弱,从而总的效果是两道扫掠激波与边界层的相互作用强度比一道扫掠激波的弱;两道扫掠激波的气流总偏转角与一道扫掠激波的相同,相交后汇聚成的激波强度与一道扫掠激波的基本相同,之前被两道扫掠激波"扫"起来的边界层在汇聚激波作用下还呈现锥形流动,分离线和来流的夹角也与一道扫掠激波的基本相同。

In order to seek a sidewall compression method to weaken the interaction between swept shock waves of the same side and boundary layers, the three-dimensional flat-plate boundary layer generated by the interaction of two swept shock waves of the same side and the flat-plate boundary layer was numerically studied. The flow mechanism of this three-dimensional boundary layer was analyzed. Also, the three-dimensional boundary layer was quantitatively compared with the one generated by one swept shock wave which has the same flow deflection angle. The results show that, in the case of two swept shock waves, the first swept shock wave makes the boundary layer next to the sidewall thinner, so the interaction between the second shock wave and the boundary layer in the attachment region becomes weaker, leading to the total effect that the interaction between two shock waves and the boundary layer is weaker than that at the one swept shock wave case; the total flow deflection angle of two swept shock waves is the same as one shock wave case, so the strength of the converged shock wave is essentially the same; the three-dimensional boundary layer generated by the swept shock is still conical, and the angle between the separation line and the inflow is essentially the same with the one swept shock case.