Numerical simulation of the inner flow in a centrifugal pump with OpenFOAM

The present situation about the numerical simulation of the inner flow in centrifugal pumps was analyzed. To improve the accuracy of pump inner flow simulation, it was inevitable to adopt open source computational fluid dynamics(CFD)codes. The compatibility of open field operation and manipulation(OpenFOAM)is better than that of other open source CFD codes. General grid interface(GGI)programs were added to the original computation codes of OpenFOAM to consider the rotor-stator interaction. The new computation procedure was applied to simulate the inner flow in a centrifugal pump, whose specific speed was 117.8.Three flow rates, 0.8Qd, 1.0Qd and 1.2Qd, were considered in detail. The calculation data were compared with experiment results and the law of impeller inner flow was analyzed. The results showed that the minimal relative discrepancy of head was about -3.5% under 1.0Qd, while the maximal was -6.4% under 0.8Qd; Absolute discrepancies of efficiencies were all within -0.5%. The simulation results indicated the behaviour of improved CFD code at design point was better than that at off-design point. In addition, pressure and relative velocity distribution of the flow field in the centrifugal impeller agree with the well known inner flow law.