带前输出轴直升机进气道侧滑特性

本文针对带有前输出轴直升机进气道结构特点 ,以实验的方法 ,在直升机飞行包线范围内 ,着重研究在侧滑角从 0°到 1 3 5°状态下的直升机进气道流场特性 ,测量分析了沿程静压分布、进气道出口截面流场畸变指数、总压恢复系数等进气道性能参数。研究结果表明 ,这类进气道在各种侧滑状态下总压恢复系数较高 ,且与侧滑角的关系不大。但是进气道内气流分离的区域和出口截面流场畸变指数却与侧滑角的大小密切相关。其中在侧滑角为 90°时 ,进气道出口截面流场品质最佳 ,而当侧滑角大于 90°时 ,出口流场迅速恶化

Characteristics of Helicopter Inlet with Front Output Shaft at Yawed Flight

An experimental study of the flow in a helicopter inlet with front output shaft was completed in low speed wind tunnel.The flow characteristics of the inlet in the flight envelope,in particular at yaw angles from 0° to 135°were investigated.The static pressure distributions along the duct,distortions of the flow field at the inlet exit section and total pressure recovery coefficients had been measured and analyzed.The results show that total pressure recovery coefficient of this type inlet is increased in every yawed flight,and are less related to the yaw angle.But the regions of local flow separation and distortion factor of the flow at the exit section are relevant closely to the yaw angle.Moreover,the characteristics of the flow at the exit section is the best at yaw angle equal to 90 degree,but these characteristics will deteriorate abruptly as the yaw angle is more than 90 degree.