Steady and Unsteady Flow inside a Centrifugal Pump for Two Different Impellers

Various parameters affect the pump performance. The impeller outlet diameter, the blade angle, the blade number and casing are the most critical. In this study, experimental and numerical investigations are carried out for two impellers different in diameter with the same casing. Numerical simulation of the whole machine (impeller, vaneless diffuser and volute) is performed using CFX-Tascflow commercial code. A frozen rotor simulation model is used for the steady state calculations and the rotor/stator model is used for the unsteady one. The model pump has a design rotation speed 2800 rpm and two impellers with 7 blades (70 mm and 105 mm outer diameters). For each pump, the performance measurements are measured and CFD analyses are carried out for different flow rates for steady and unsteady calculations. Finally, a comparison between the CFD and performance measurement is fairly good.