直升机旋翼下洗流对涡轴发动机进气道的影响数值模拟研究

Numerical Simulation of the Influence of Helicopter Rotor Downwash on Turboshaft Engine Inlet

本文介绍了直升机旋翼下洗流对涡轴发动机进气道的影响研究。旋翼流场数值模拟采用基于滑移网格技术求解Navier-Stokes方程的方法,涡轴发动机模拟采用在进气道的出口和尾喷管的进口施加边界条件的方法。通过直升机机体/旋翼/涡轴发动机进排气一体化流场仿真,获得了不同飞行状态下涡轴发动机进气道的流场特性,并且初步分析了旋翼下洗流对涡轴发动机进气道的总压损失系数和总压畸变指数的影响。研究结果表明,相比前飞状态和斜下降状态,悬停状态下涡轴发动机进气道受旋翼下洗流的影响最大,进气道出口的总压损失系数和总压畸变指数最大;旋翼转速增大,进气道的总压损失系数和总压畸变指数也相应增大,进气道的性能降低。

The influence of the rotor downwash on the turboshaft engine inlet was studied.The numerical simulation of the rotor flow field adopts the method of solving Navier-Stokes equation based on sliding mesh technology,and the method of imposing boundary conditions is adopted for the turboshaft engine simulation.Through the integrated flow field simulation of the inlet and exhaust of the helicopter rotor/airframe/engine,the flow field characteristics of the turboshaft engine inlet under different flight conditions are obtained,and the effect of the rotor downwash on the the total pressure loss coefficient and total pressure distortion index of the turboshaft engine inlet is analyzed.The results show that,compared with the forward flight state and the oblique descent state,the turboshaft engine inlet is most affected by the rotor downwash in the hovering state,and the total pressure distortion index of the inlet is the highest,and the total pressure loss coefficient is the largest;As the downwash speed increases,the total pressure loss coefficient and total pressure distortion index of the inlet also slightly increase,and the performance of the inlet decreases.