CFD analysis of performance change in accordance with inner surface roughness of a double-entry centrifugal pump

In this study, the performance change of a double suction centrifugal pump (Q = 60 m(3)/min, H = 97 m) was analyzed using Computational fluid dynamics (CFD) to investigate the effects of internal surface roughness of pump components. The calculated performance of the pump using CFD is in strong agreement with the experimental results, which used a smooth wall case. In terms of the predicted total pump efficiency with the surface roughness case, the CFD results indicate that the pump efficiency is reduced by approximately 3.0 %. CFD results reveal that the most significant roughness effect on the pump components is that of the impeller, whereas the smallest effect is that of the inlet casing. Furthermore, the CFD results demonstrate that the pump performance is strongly dependent on the outward shroud surface roughness of the impeller.