Centrifugal Pump Pressure Pulsation Prediction Accuracy Dependence Upon CFD Models and Boundary Conditions
Unsteady CFD simulations for a low specific speed open faced impeller centrifugal pump operating with and without balancing holes and having cut-away sections of the impeller are performed and compared to experimental data obtained using the actual pump simulated. For this simulation, the entire pump from suction inlet to exit flange is modeled. General pump performance characteristics are compared between the actual pump and the simulation. Pressure pulsation data are recorded at various locations in the pump using flush mounted pressure transducers and directly compared to the simulation results. Pressure spectrum data are used to evaluate the effects of three different boundary conditions upon the accuracy of the pressure pulsation simulations as well as the overall pump performance. These boundary conditions are a) fixed inlet and exit pressure, b) mass flow rate inlet condition with outflow exit, and c) target mass flow rate inlet with outflow exit which lets the inlet pressure fluctuate. All of these are available in the commercial CFD package utilized. Based upon comparisons between CFD simulations and experimental data for both the steady and unsteady conditions, the mass inlet condition is found to produce the best overall results for the installed pump.