DSI两级斜切后掠唇口对飞机外流的影响

Influence of DSI two-stage swept back lip on aircraft external flow

为研究无隔道超声速进气道(DSI)唇口对飞机整体气动性能的影响,采用数值仿真方法对全机进行了三维内外流场的数值模拟。以进气道性能最优的单级后掠唇口为基准模型,在此基础上设计了两级斜切后掠唇口模型。研究发现与基准唇口相比,两级斜切后掠唇口模型不仅能够提高进气道的总压恢复系数,改善进气道的出口流场畸变;而且能够通过改变机翼表面的压力分布来改变机翼的升力,进而影响飞机整体的气动力特性。结果表明:在本文所研究的两级斜切后掠唇口不同的二级后掠角变化范围内,存在最佳后掠角度35°可以进一步提高全机气动布局升阻比,升阻比提高了0.034,其增益可达2.1%。

In order to study the influence of diverterless supersonic inlet(DSI)lip on the overall aerodynamic performance of the aircraft,the internal and external flow fields were simulated by numerical simulation method.Based on the benchmark model of single-stage swept back lip with the optimal inlet performance,a two-stage swept back lip model was designed.It was found that compared with benchmark model,the two-stage swept back lip model can not only improve the total pressure recovery coefficient and reduce the flow distortion index of the inlet,but also change the lift of the wing by changing the pressure distribution on the wing surface,and then affect the aerodynamic characteristics of the aircraft as a whole.Within the range of two-stage sweep back angle in this study,an optimal angle 35°can help further improve the lift-drag ratio of the aircraft aerodynamic layout by 0.034,and the gain up to 2.1%.