This paper treats the flow instabilities in a vaned diffuser by using CFD. A commercial code with the standard κ-ε turbulence model was used for the present work. It was found that the flow instabilities in the vaned diffuser: i.e., rotating stall, alternate blade stall, and asymmetric stall, could be simulated 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.

Issue Section:
Technical Papers
Keywords:
pumps, computational fluid dynamics, flow instability, turbulence, Navier-Stokes equations, finite volume methods, flow separation
Topics:
Diffusers, Flow (Dynamics), Impellers, Pressure, Pumps
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Copyright © 2002
 by ASME
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