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 cla rify the effects of spanwise distribution of cascade characteristics, A sem i-actuator disk model of annular cascade is employed. Linear spanwise distr ibutions of the local performance slope are considered to examine the effec ts of the three-dimensionality in the cascade characteristics. Many eigenva lues 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. I t was also found that uneven spanwise distribution of cascade characteristi cs makes the 0th mode more unstable, and makes the amplitude of the disturb ance larger at radial locations where the positive slope of the performance is larger.