唇罩激波/边界层干扰的壁面鼓包/次流循环组合控制方法研究

Control of Cowl Shock/Boundary Layer Interaction by Bump/Secondary Flow Circulation

为了对超声速、高超声速进气道内多道连续唇罩激波/边界层干扰现象进行有效控制,提出了一种壁面鼓包/次流循环的组合控制方法,并对相关流动机理及参数影响规律进行了研究。结果表明:通过小尺度鼓包迎风侧弱压缩波束的预增压效应,实现对第一道唇罩激波/边界层干扰的控制;同时,在压差力的驱动下,鼓包下游第二道唇罩激波作用导致的边界层分离包内的低能流进入次流循环装置,并从上游压缩面上的吹气缝喷出,实现对第二道唇罩入射激波的控制。在鼓包与次流循环装置的共同作用下,两道唇罩激波产生的边界层分离被有效隔离并分别控制。同时,本控制方案不会造成进气道捕获流量的损失。相较于无控制方案,鼓包/次流循环组合控制方案可以在来流马赫数为3.95~6.95内实现对多道连续唇罩激波/边界层干扰的控制,改善内通道中的流动,提高进气道的总压恢复性能,最大改善幅度可以达到15.7%。此外,为保证控制效果,应选择合适的吹气缝和引气缝位置。

To control the continuous cowl shock/boundary layer interaction in a supersonic/hypersonic inlet,a new control method by the combination of a bump and secondary flow circulation is brought forward. The flow mechanism and effects of parameters are investigated by computational method. Results show that the first cowl shock/boundary layer interaction can be controlled by the precompression effect induced by the weak compression waves at the windward side of the small-scale bump. At the same time,the low-momentum flow in the separation bubble induced by the second cowl shock is driven into the secondary flow circulation device by the pressure differential and then injected into the primary flow through the blow slot in the inlet ramp,which controls the second cowl shock/boundary layer interaction. Under the combined effect of the bump and secondary flow circulation,the separation induced by the two cowl shocks is effectively isolated and separately controlled. Meanwhile,this control method can avoid the loss of the inlet captured mass flow rate. As compared with the uncontrolled case,the bump/secondary circulation control method can realize the control of the continuous cowl shocks/boundary layer at the freestream Mach number range of 3.95~6.95. The flow in the inlet can be enhanced and the total pressure recovery ratio is improved. The most improvement of the total pressure recovery ratio can reach15.7%. In addition,the locations of the blow slot and the bleed slot should be set appropriately to ensure the control effect.