直升机旋翼功率传递系数确定方法

Identification of helicopter rotor power transfer coefficient

摘要:

阐明了在现有的直升机性能计算中,旋翼功率传递系数总是假定为常数,这种处理方法具有很大的局限性。文章详细地介绍了从飞行力学的角度来确定直升机平直飞行时的旋翼功率传递系数。首先,通过飞行力学中的配平计算得到直升机在不同飞行速度下的旋翼和尾桨的需用功率；然后,用试飞实测方法确定除旋翼和尾桨外的功率损耗；最终,得到直升机在不同飞行速度下的旋翼功率传递系数。认为:由于旋翼、尾桨的需用功率由飞行力学的配平方法得到,其结果能合理地反映飞行状态和直升机尾部构型等因素对它们的影响,加上除旋翼和尾桨外的功率由试飞实测得到,因而文中所述的直升机旋翼功率传递系数能更准确地反映直升机的功率传递关系。

Abstract:

The helicopter rotor power transfer coefficient in the performance calculation is always assumed constant. In this paper, the rotor power transfer coefficient is determined from the point of helicopter flight dynamics. Firstly, the trim calculation is conducted at various forward speeds to determine the main rotor and tail rotor powers. Then the additional power consumed by accessories other than main and tail rotors is identified by flight test. The variation of rotor power transfer coefficient with forward speed is obtained according to the powers in corresponding forward speed. The result is improved since the rotor transfer coefficient is determined based on the powers in flight. In Addition, the method described in this paper can consider the effect of vertical empennage and different tail rotor type such as ducted tail rotor.