螺旋桨-自由涡轮涡桨发动机稳态/过渡态数值模拟

为实现对涡桨推进系统整体推进性能的数学模型模拟，以螺旋桨/桨扇作为受飞行外流条件影响的推进系统内流部件之一，引入其特性图，用跟随流量方法解决螺旋桨-自由涡轮转子与涡桨发动机燃气发生器的流量平衡、功率平衡，发展了螺旋桨-自由涡轮涡桨发动机内流特性部件法数学模型，实现了对该类涡桨系统稳态/过渡态的数值模拟。对某8MW三轴桨扇发动机的台架转速特性和飞行任务剖面特性的数值模拟结果表明:该数学模型可以较为准确模拟出包含桨叶变动桨距角、攻角等在内的外流螺旋桨/桨扇部件工作点详细参数，和高度、速度、涡轮前温度同时变化的多条件、多变量涡桨发动机的稳态/过渡态推力、推力耗油率等特性. 

Steady- and transient-state numerical simulation of turboprop engine of propeller-free-turbine types

In order to simulate the performance of an integral turboprop propulsion system by a mathematics model, the propeller was taken as one of the internal flow components of the turboprop engine greatly influenced by external flow under the flight conditions. With introduction of propeller map and an imaginary mass method, this component-level turboprop engine mathematics model balanced two mass flow rates and powers of the propeller-free-turbine rotor and gas generator. The corresponding code was developed, and the steady- and transient-state sea-level rotational speed characteristics and flight mission profile characteristics of an 8 MW propfan propulsion system were simulated. The numerical simulation results show that, this mathematics model can successfully simulate the detailed performance of the variable pitch angle and the angle of attack of propeller or propfan on the cooperating points, and also the steady- and transient-state characteristics including the thrust and the specific fuel consumption of thrust of turboprop engine, while the environmental and adjusted parameters like altitude, velocity and turbine inlet total temperature are varying.