Design and numerical characterization of a first stage of a high capacity multistage centrifugal pump

In this paper, a numerical characterization of a first stage of a high capacity multistage centrifugal pump was performed for very high flow rates. A particular emphasis was placed on the diffuser design procedure. For this purpose, the equations of the continuity and the Navier-Stokes accounting for the boundary conditions were used by mean of ANSYS-CFX code to describe and to simulate the complex liquid flow in the multistage centrifugal pump. In order to identify the key parameters of the diffuser that can improve the pump stage performances, the effects of the inlet height of the diffuser vanes, the number of the diffuser vanes, the number of the diffuser return vanes, and the gap between the impeller and the diffuser on the pump stage head, brake horsepower and efficiency were analyzed. The validation of the developed model of a first pump stage was done comparing results of numerical simulations and experimental results obtained from a pump manufacturer.