Effects of Spanwise Distribution of Cascade Characteristics on Rotating Stall-A Three-Dimensional Linear Analysis

A three-dimensional linear analysis of rotating stall is carried out to clarify the effects of spanwise distribution of cascade characteristics. A semi-actuator disk model of annular cascade is employed. Linear spanwise distributions of the local performance slope are considered to examine the effects of the three-dimensionality in the cascade characteristics. Many eigenvalues were found corresponding to various kinds of radial mode. It was found that the 0th order radial mode is more unstable than higher order modes. It was also found that uneven spanwise distribution of cascade characteristics makes the 0th mode more unstable, and makes the amplitude of the disturbance larger at radial locations where the positive slope of the performance is larger.