Numerical study of rotating stall in a pump vaned diffuser

This paper treats the flow instabilities in a vaned diffuser by using CFD. A commercial used for the present work. It was found code with the standard K-E turbulence model was use that the flow instabilities in the vaned diffuser: i.e., rotating stall, alternate blade stall, and asymmetric stall, could be simulated It by the present calculations. These instabilities were observed in a range with negative slope of the pressure performance curve of the diffuser. The rotating stall onset flow rate is larger for the case with larger clearance between the impeller and diffuser vanes.