基于冷气预冷技术的高马赫数涡轮发动机建模与仿真研究

For the thermal protection of turbine components of high-speed gas turbine engines, a variable cycle turbofan (VCTF) engine with cooled cooling air (CCA) technology is taken as an example. This paper establishes the library of fuel thermal physical properties, the simulation model of electric fuel pump and the air-fuel heat exchanger, and improves the burner and turbine simulation model. The engine performance simulation model with variable bleeding air flow that can control the turbine blade temperature was developed. The simulation results show that at the design point of Mach 3 and altitude 20km, introducing the CCA technology can reduce the temperature of turbine cooling air by 181K, reduce the relative bleeding air flow by 22.04%, and increase net thrust and specific impulse by 2.03% and 0.66%, respectively. During the throttling state of Mach 3, the thrust of the engine with turbine blade temperature control decreases faster with the decrease of the rotational speed, but the temperature drop on the air side of the air-fuel heat exchanger is up to 240K, and the total pressure loss is further reduced. Along the flight trajectory, introducing turbine blade temperature control can improve the engine thrust when the flight Mach number is greater than 1.8 and improve specific impulse when the flight Mach number is smaller than 1.8. The performance design of the air-fuel heat exchanger at the maximum heat load of the engine is the key to determining the bleeding air temperature drop and the backflow margin of turbine bleeding air.