The Effect of Blade And Casing Geometry Modification on a Regenerative Pump Performance

The regenerative pump is a rotor-dynamic turbomachine capable of developing high pressure rise at low flow rates.In this paper, the CFX software is carried out to investigate the performance of a regenerative pump considering the modification in blade and casing geometry. For this purpose, the blade shape changes to the bucket form. In this study, the fluid flow is considered steady-state and frozen rotor technique is used. For the turbulence modeling, realizable k–ε model is chosen which is suitable for complex shear flows involving in rapid strain, swirl, vortices and locally transitional flows. Results of the numerical simulation show that the modified blade angle to achieve the maximum efficiency is about 40 degree. The performance curves of the new designed pump extracted from CFD simulation, have been compared with the experimental results of regenerative pump with radial blades. Results show that the efficiency of the pump with bucket-shape blades and new casing with central core is improved relative to radial blades one. Also, the head coefficient and the number of the flow rotations increases while the flow coefficient decreases. The turbulence intensity decreases during rotation of fluid using central core in the casing and as consequent turbulent losses is reduced.