Study on surge and rotating stall in axial compressors (1st report, a summary of the measurement and fundamental analysis method)

In multistage axial compressors used for gas turbine engines, it is important to clarify unsteady phenomena such as surge and rotating stall. The purpose of this study is to develop a practical analysis method for both the surge and rotating stall in axial compressors. In this paper, firstly, some characteristics of the unsteady phenomena in axial compressors are summarized, derived from the measurements in test compressors. Secondary, a numerical method for the unsteady phenomena assuming incompressible flow is described. A feather of the method is solving the equations by Galerkin's method with the circumferential flow distortion expressed in the form of a high-order Fourier series. Finally, the usefulness of the method is examined by some results from a parameter survey computation and by a comparison with the measured results in a 3-stage test compressor.