某型发动机试验数据的Lyapunov指数研究

研究某型发动机的八级轴流压气机级间压力信号的最大Lyapunov指数,推断出失速和喘振的起始点具有相同的动力学特性:都为某一极限环边界上的点。提出了一种新的压气机最先失速级检测方法:将最大Lyapunov指数的零点作为失速的判据,最大Lyapunov指数最先达到零点的那一级就是最先失速级。计算结果表明该方法可以在压气机深度失速前0.2s检测到失速起始信号,且最先失速级为第三级。

Largest Lyapunov Exponents of Engine Experimental Data

The largest Lyapunov exponents of the pressure signal of a certain engine with eight axial compressor stages are investigated: The stall and surge inception points possessing the same dynamic characteristics are all located on the boundary of a limit circle.A new method for detecting the first stage of stall is presented,where the largest Lyapunov exponent zero point is regarded as the initial stall of the compressor,and the stage within which the largest Lyapunov exponents firstly reaches to zero is indicated as the first stall one.The computational results demonstrate that the method enables to detect stall inception signal of compressor 0.2s before the beginnig of deep rotating stall,and the third stage is noted as first stall stage.