边界层抽吸效应对分布式推进系统气动性能影响数值研究

为探究边界层抽吸（BLI）效应对飞机的气动性能影响，采用基于沿流线体积力模型的飞机/发动机一体化数值模拟方法对某分布式推进系统进行了计算和分析。结果显示，BLI效应主要影响飞机中心体部分及发动机外整流罩的气体流动，对翼身融合体（BWB）的融合段及外翼段的升阻力影响较小。保持飞行条件和飞行攻角不变，飞机的升、阻力系数均随着无量纲化的发动机流量增加而增大，存在最佳无量纲化的发动机流量对应最大升阻比。发动机的安装位置直接影响机身表面的局部超声区和整流罩外的激波分布，布局在机身尾缘处会获得更好的升阻比，最大升阻比对应的无量纲化的发动机流量为0.65。 

Numerical investigation on the effects of boundary layer ingestion on aerodynamic performance of distributed propulsion system

To explore the effect of boundary layer ingestion (BLI) on the aerodynamic performance of aircraft, the aircraft/engine integrated simulation method based on the streamwise-body-force model was used to calculate a distributed propulsion system. Results show that BLI mainly affect the flow field of center body parts and cowling of engines, but yield small impact on lift and drag of the blending field and outer wing of BWB. Under the same flying conditions and constant angle of attack, the lift coefficient and drag coefficient increase with the increase of the non-dimensional mass flow rate of the engines. Therefore, a best non-dimensional mass flow rate of the engines corresponding to maximum lift-to-drag ra-tio exists. Engine installation location directly influences the localized supersonic flow of fuselage surface and the shock wave distribution of cowling. Layout of engines at the trailing edge could get better lift-to-drag ratio, where the non-dimensional mass flow rate of the engines corresponding to maximum lift-to-drag ratio is 0.65.