自转旋翼的气动优势和稳定转速

 旋翼机在正常飞行中和直升机在自转下滑时,其旋翼都处在自转状态。从建立自转旋翼的气动模型入手,通过与直升机正常工作状态下的旋翼的气动特性的对比,得出自转旋翼具有较好的气动环境和更高的效率;讨论了旋翼机的稳定转速与总距角、前飞速度以及桨盘迎角的关系,通过分析说明在设计旋翼机时,可选择一固定总距,使旋翼机在相当宽的飞行范围内,只需小幅度调整桨盘迎角就可保持稳定飞行。

AERODYNAMIC VIRTUE AND STEADY ROTARY SPEED OF AUTOROTATING ROTOR

The main rotor is in the condition of autorotation w hen a gyroplane is in flight or a helicopter in autorotation. After an aerodynamic model of a autorotating rotor was established, the conclusion is drawn that the autorotating rotor of the gyroplane has a better aerodynamic condition and hig her efficiency compared with the rotor of the helicopter .The analysis of the relations among steady rotary speed, collective pitch, forward speed and rotor disk angle of attack showed that a regular collective pitch and rotary speed can be selected to fit steady flight in a considerable wide range of flight speed only by adjusting the rotor disk angle of attack a little.