An Investigation of Post Stall Transients and Recoverability of Axial Compression Systems: Part I — A Simplified Method

Using the theory developed by Moore and Greitzer, a simplified approximate method is proposed to calculate the evolution of the mass flow, pressure rise, and the growth and decay of rotating stall cell during post stall transients or recovery process in multistage arial compression systems. The method leads to a set of three simultaneous nonlinear first order partial differential equations, and for the numerical solution, a simple explicit time marching method can be used. It is shewa that a study of rotating-statt-like and surge-like motion, recoverability from rotating stall or surge, and limited parameters can be carried out through this method. It has been found that, except the two general types of distinct flow instabilities (rotating stall and surge), there is another type of instability in arial compression systems, which has the basic characteristic of both rotating stall and surge. Some qualitative comparisons with available experimental results and some qualitative comparisons with test data are made in this paper. It shows that the proposed model is very simple, accurate and dependable.