开式转子发动机计算模型及调节研究

Research on Open Rotor Engine Caculating Model and Control Schedule

目前先进的开式转子发动机多采用变桨距、双排共轴对转桨作为推进部件。采用双排桨的气动计算方法,根据单排桨特性图计算对应的双排对转桨特性图,验证对转桨性能计算模型。在双轴涡轮喷气发动机计算模型的基础上,添加动力涡轮、行星差动齿轮和双排对转桨,组成开式转子发动机计算模型。采用该模型研究了开式转子发动机的调节计划,对比了等转速和等叶尖速度调节的不同,以及对开式转子发动机高度速度特性的影响,并使用美国PROOSIS模型对计算结果进行验证。结果表明:开式转子发动机模型计算精度较高,可较准确地研究不同设计参数和调节规律下发动机的总体性能,其中固定桨扇叶尖速度的调节计划在较低飞行速度下具有高推力、低油耗的优点,可以获得较好的全包线性能。

Counter-rotating coaxial propellers with variable pitch blades are mostly implemented in the current advanced open rotor engine. An aerodynamic computing method of counter rotating propellers was verified through calculating the counter-rotating propeller map using two single propeller maps. Basing on the aerodynamic and thermal model of a two-spool turbojet engine, an open rotor performance model was established by adding a power turbine, a differential planetary gearbox and a pair of counter rotating propellers. With this model, the control schedules were studied. The difference between constant propeller speed strategy and constant tip speed strategy , their influences to the altitude and velocity characteristics were compared respectively. The results were demonstrated to be accurate by using the data of PROOSIS model, and the performance of open rotor engine under various design parameters and different control schedules could be precisely studied. Results show that the constant tip speed strategy had advantage of high thrust with low fuel consumption at a lower flight speed, and better performance of the whole envelope would be obtained.