Applications of different turbulence models in simulations of a large annular volute-type pump with the diffuser

Abstract

It's necessary to choose a good turbulence model for the reliable numerical simulation of the pump in hydraulic optimization. In this paper, the four widely used turbulence models are selected and compared in three dimensional steady numerical simulations for a large annular volute-type pump with the diffuser. The pump performance is verified by the experiments in an open test rig. The results show that the SST turbulence model gets closer values to the experiment in predicting head. The trend of the pressure distribution at design condition for the four models on pressure side is very similar, which first increases and then decreases along the streamline. There are a minimum at 0.05 and a maximum at 0.8 of the length of the streamline, due to the existence of vortices. The predicted pressure distribution on the suction side is more similar. With the increase of flow rate, the flow field in the impeller becomes more uniform, and the number as well as the size of the vortices decrease. Secondary flow is observed in the volute and three vortices are found near the upside of the volute.