涡轮螺旋桨飞机单发自转状态的运动分析

Motion analysis on turboprop aircraft with single propeller auto-rotate after the engine failed

多发涡轮螺旋桨飞机单发停车,螺旋桨进入自转状态产生负拉力,这一特情必将危及飞行安全。首先说明螺旋桨自转工作状态,负拉力产生机理和随飞行速度的变化规律;然后分析螺旋桨不同工作状态下,滑流对机翼升阻力的影响,并应用螺旋桨载荷系数推算两翼升阻力差及横航向力矩,以此解决此种状态气动数据资料的不足问题;在此基础上,建立飞机全量动力学方程,根据实际舵面输入,仿真解算飞机的动态响应过程,与实际飞参数据进行对比;最后讨论分析得到此种特情影响飞行安全的主要因素是机翼升阻力差引起的横航向力矩和副翼效能减小等。研究结果对涡轮螺旋桨飞机设计阶段尽量避免特情发生和飞行阶段合理处置特情,保障安全具有借鉴意义。

If the propeller auto rotates after one of engines on turboprop aircraft failed,the auto-rotate propeller will produce negative pulling force,which will endanger flight safety.Firstly,this article introduces the propeller auto-rotate states,negative pulling force mechanism,and changes law according to air speed,then analyzes the influences of slipstream on lifts and drags according to states of propellers,and apply the propeller load coefficient to calculate the difference in lift resistance and lateral heading moment between the two wings,in order to solve the problem of insufficient aerodynamic data in this state.Based on all above,the full state hydrodynamics were established.The dynamic states of airplane were simulated and calculated according to actual control surfaces inputs,and compared to actual flight data.Finally,it was discussed and analyzed that the main factors influencing flight safety due to this special situation were obtained,which are decreases of lateral directional moments and aileron efficiency caused by errors between lifts and drags on different wings.The conclusions are worth of reference to guarantee flight safety,both for turboprop aircraft design to avoid the situation and managing the situation in flight.