On the Partial Flow Rate Performance of Axial-Flow Compressor and Rotating Stall : 1 st Report, Influences of Hub-Tip Ratio and Stators

Abstract

Some experimental investigations on unstable performances in partial flow rate regions of a single stage axial-flow compressor and its rotating stall are described. In order to explain the unstable operations related with rotating stall, the influences of hub-tip ratio and rotor-stator distance on the performance curves and rotating stall characteristics are discussed. Performance curves, total pressure distributions under different operating conditions, size of stall cells and stall velocity are shown, Many types of rotating stalls, such as large stall, small stall, partial span stall and full span stall are investigated with different hub-tip ratios and stator positions. When large stall occurs, the discharge pressure discontinuously decreases and a slope of the performance curve becomes positive. In the case of small stall, however, the pressure decreases slightly and continuously. The partial flow rate performance is severly affected by the size of stall cell.