Limits of Rotating Stall and Stall in Vaneless Diffuser of Centrifugal Compressors

Based on the theory in Reference (3), the flow behavior is predicted in four vaneless diffusers with different geometries at the flow rates just before rotating stall and just before stall, which have been experimentally determined. Since the predicted velocity distributions at the critical conditions are physically reasonable for rotating stall and for stall are tentatively set so that the critical conditions are predictable using the theory. Prediction is made for two cases for backward leaning blade impellers and three cases for radial blade impellers in the literature in addition to the authors’ experiments. Satisfactory results are obtained except one example.