转速对航空动力装置动力性能和经济性能的影响

Effect of Rotating Speed on Dynamic and Economic Performance of Aero Power Plant

为探究发动机转速对某中空长航时无人机动力装置的动力性能和经济性能的影响,结合发动机速度特性曲线、耗油率特性曲线、高空特性曲线及螺旋桨效率曲线,在某无人机飞行速度范围内,选取典型发动机油门匹配不同发动机转速,通过理论计算与试验相结合的方法,评估动力性能和经济性能的变化情况。研究表明:对于所研究的航空动力装置,在所研究的发动机转速范围内,推力随着发动机转速的增加而增大,单位推力耗油率则随着发动机转速的增加先减小后增大,即存在最经济转速,且发动机油门位置越大,对应的最经济转速也越高。为保证动力性能和经济性能,各油门设定的转速应避免设置在最经济转速之下。对于所研究的航空动力装置,在最大连续工况条件下,当飞行速度一定时,动力装置的推力、螺旋桨效率随着飞行高度的增加而降低,单位推力耗油率则随着飞行高度的增加先增加后降低。在飞行高度一定时,动力装置的推力随着飞行速度的增加而降低,而螺旋桨效率、单位推力耗油率则随着飞行速度的增加而上升。

To investigate the influence of engine speed on the power performance and economic performance of a certain power plant in a medium-altitude long-endurance(MALE)UAV,combining with the engine speed characteristic curve,fuel consumption character-istic curve,high-altitude characteristic curve,and propeller efficiency curve,typical engine throttle was selected within the flight speed range of a UAV to match different engine speeds.Through theoretical calculation and experimental methods,the changes in power performance and economic performance were evaluated.The research shows that for the power plant under study,within the range of engine speed under study,the thrust increases with the increase of engine speed,and the sfc generally decreases first and then increases with the increase of engine speed,that is,there is a most economical speed,and the greater the throttle position of the engine,the higher the corresponding most economical speed.To ensure the power performance and economic performance,the matching speed of each throttle shall not be set below the most economical speed.For the studied aviation power plant,under the maximum continuous working condition,when the flight speed is constant,the thrust and propeller efficiency of the power plant decrease with the increase of flight altitude,and the sfc increases first and then decreases with the increase of flight altitude.At a certain flight altitude,the thrust of the power plant decreases with the increase of flight speed,while the propeller efficiency and sfc increase with the increase of flight speed.