压缩机系统高阶Moore-Greitzer模型的动态行为分析

Dynamics and Analysis of Higher Order Moore-Greitzer Model in Compression System

以压缩机系统不稳定现象的MG(Moore-Greitzer)模型为基础提出了其高阶Galerkin扩展形式,并进行了稳定性分析,得到旋转失速和喘振的条件:失速仅受阀门参数的影响,而喘振受阀门参数、稳定性参数两者的综合影响.然后,在压缩机性能曲线为三次曲线的典型条件下,从稳定状态到喘振状态分阶段对系统的动态行为进行数值仿真.结果表明:高阶速度扰动模态波在失速初始阶段严重影响一阶模态波,而在过失速阶段则影响不大;在相同的初始条件下,高阶扩展模型失速发展的速度比一阶模型快了约16%,因此可以更早地检测到失速的发生;高阶模型对初始扰动更加敏感.

The higher order Galerkin expansion of the Moore-Greitzer model of instabilities in compression systems was proposed. The identification of stability was conducted based on this model. The conditions of emergence of rotating stall and surge were concluded qualitatively. Stall only depends on the throttle parameter, but surge depends on both of throttle parameter and stability parameter. Then dynamic behavior was piecewise investigated from axisymmetric steady flow to surge with a cubic compressor characteristic. Simulation results show that the higher-or- der disturbance velocity potential harmonics strongly interact with the first harmonic during stall inception. Forming stall behavior from axisymmetric steady flow in higher-order model is faster by about sixteen percent than in first order model. Thus the occurrence of unstable phenomena at the onset is earlier. Initial disturbance is more sensitive to the higher order model.