Fundamental Analysis on Rotor-Stator Interaction in a Diffuser Pump by Vortex Method

Abstract

A two-dimensional unsteady flow was calculated within a whole stage of a diffuser pump to investigate pressure fluctuations due to the interaction between impeller and diffuser vanes by using the vortex method, in which vortices shedding from solid boundary were determined by the basic governing equation. The Petrov-Galerkin Method was applied to yield the solutions that satisfy the boundary conditions in an integral sense, and it improved the stability and accuracy of the numerical solutions greatly. A new scheme was also proposed to improve the unsteady pressure evaluation by a boundary integration method in the rotor-stator interaction problem. Moreover, for a more realistic prediction of the pressure fluctuations, the inlet flow was supposed to change with time so that pumping system may balance. The calculated time-varying flow rate, total hydraulic head rise and pressure fluctuations in the vaned diffuser passage, were compared with the measured and calculated ones by other methods. Calculated unsteady pressure fluctuations in the vaned diffuser passage showed good agreement with the experimental data and the CFD calculated ones.