热效应对涡喷发动机过渡过程的影响

涡轮喷气发动机的过渡过程是个很复杂的物理过程。为了分析发动战的加速性,工作稳定性以及设计发动机燃油控制系统,需要建立一个精确的过渡过程数字模型。目前比较通用的过渡过程数学模型,大案是只考虑发动机转子惯性和发动机流道上的容腔影响。许多计算证明,对于一般过渡过程容腔影响极小,完全可以忽略不计。通过对一台单轴涡轮喷气

THERMAL EFFECTS ON TRANSIENT PROCESS OF A TURBOJET ENGINE

The mathematical models commonly used for dynamic process of turbojet or turbofan engine consider only the rotor inertia and gas path volume dynamics. Usually the gas path volume of an aeroengine is not great, so the effect of volumedynamics on normal transient process is negligibly small. The thermal effectsinclude transient heat transfer and the component efficiency changes caused by clearance variation with temperature in the components of compressor and turbine.A single-shaft turbojet engine has been tested for cold and hot transient processes. The comparison between the cold and hot transient test results shows that the thermal effects have significant influence on the acceleration time, the changing rate of aerothermodynamic parameters with engine speed, etc. The experimentalinvestigation demonstrates that the thermal effects must be taken into account so as to establish an accurate mathematical model for the transient process of turbine engines.