背撑发动机进排气对翼身融合民机气动特性影响

Intake and exhaust effect on aerodynamic characteristics of blended wing body civil aircraft with podded engines

针对翼身融合(BWB)背撑发动机布局民机的发动机与机体流动干扰问题,以项目团队研究的某BWB布局民机方案为研究对象,采用CFD方法研究了发动机进排气对全机低、高速气动特性的影响规律及其流动机理。结果表明:进排气效应主要影响飞机的高速阻力特性,随着发动机进气流量的减小,机体/短舱之间流动干扰加剧,机体零升阻力增加;进排气效应对低速状态升力和俯仰力矩的影响主要由发动机的抽吸作用对机体表面流动的干扰引起。发动机不同的进气流量会对全机的升阻力特性产生较大影响,在BWB布局机体/发动机一体化设计中,要充分考虑机体与动力装置之间的干扰影响,同时权衡不同进排气状态对机体和发动机当地流动的影响。

For the problem of the flow interaction between engine and airframe of blended wing body(BWB)civil aircraft with podded engines,taking a BWB civil aircraft designed by project team as the research object,the engine intake and exhaust effect on aerodynamic characteristics and its mechanism at low and high speed conditions were investigated by CFD method.The results indicate that the intake and exhaust mainly affect drag characteristics at high speed condition.As the engine intake mass flow decreases,the interaction between airframe/nacelle is intensified and the zero-lift drag of airframe is increased.The intake and exhaust effect on lift and pitching moment at low speed condition is mainly induced by the interference of engine suction effect on the airframe surface flow.The intake mass flow of engine has great effect on the aerodynamic characteristics of BWB transport.In the airframe/engine integration design of BWB transport,the interaction between airframe and engine should be considered and the effect of different intake and exhaust conditions on the local flow field of airframe and engine should be weighted.