高速直升机旋翼/螺旋桨/机身干扰特性分析

研究双拉力螺旋桨复合式高速直升机的气动特性可以为高速直升机的设计及气动优化提供参考。基 于动量源方法构建针对双拉力螺旋桨复合式高速直升机旋翼/螺旋桨/机身干扰特性数值计算及分析方法;对 孤立旋翼、旋翼/机身干扰进行算例验证;应用所构建的方法对双拉力螺旋桨高速复合式直升机悬停及前飞状 态的干扰流场进行数值模拟,分析机身对悬停流场影响及不同前飞速度旋翼/螺旋桨/机身干扰特性。结果表 明:悬停时机身对气流的阻塞作用降低了旋翼的升力,螺旋桨对旋翼下洗气流的加速作用使旋翼升力提高;低 速前飞时旋翼/螺旋桨/机身干扰较大,主要体现在旋翼下洗流造成螺旋桨滑流偏折以及机翼上表面压力分布 增大,高速前飞时这种干扰较小。

Analysis of Rotor/Propeller/Fuselage Interaction Characteristics of High Speed Helicopter

Based on the momentum source method, a numerical calculation and analysis method for the rotor/propeller/fuselage interaction characteristics of a high-speed helicopter with double-thrust-propeller was developed. The momentum source was used to replace the rotor and the propeller. Firstly, numerical examples of isolated rotor and rotor/fuselage interaction were given to verify the accuracy of the numerical method. Then, the disturbing flow field in the hovering and forward flight state of the double-thrust-propeller high-speed composite helicopter was numerically simulated by using the constructed method. The disturbance of the fuselage to the hovering flow field and the rotor/propeller/fuselage interaction characteristics at different forward flight velocities were analyzed. The calculation results show that the blocking effect of the fuselage on the airflow reduces the lift of the rotor while the propeller is under the rotor. The acceleration of the wash air increases the lift of the rotor; the rotor/propeller/fuselage interaction is greater at low-speed forward flight, which is mainly reflected in the deflection of the propeller slipstream caused by the downwash of the rotor and the increase of the pressure distribution on the upper surface of the wing, while the interaction is smaller at high-speed forward flight.