进口总压随机脉动的数值模拟方法

为了能用数值计算方式模拟动态总压畸变对航空发动机稳定性的影响,首先要模拟出进口总压的随机脉动过程.根据进口总压随机脉动的正态分布特点及相关性特征,获得了带有指数自相关函数的动态总压畸变的随机过程,同时分析了积分时间常数、时间步长以及时间长度等参数对所生成的总压随机脉动过程的影响.结果表明,为了获得较好的模拟效果,时间步长应取得较小,时间长度应取得足够的长,而积分时间常数对模拟的可靠性则影响不大. 

Numerical simulation method for stochastic fluctuation of inlet total pressure

In order to simulate the influence of the dynamic inlet total pressure distortion on the stability of the aero-engine,the stochastic fluctuation of the pressure should be first simulated.The inlet total pressure stochastic fluctuation process was simulated on the base of the normal school and auto correlation characteristic of the inlet total pressure stochastic fluctuation,and the influence of the integral time constant,time-step and time-length on the inlet total pressure stochastic fluctuation process was analyzed.The results show that the shorter time-step and longer time-length can obtain better simulate result,but the integral time constant does not affect the simulate result.