Simulation of Unsteady Interaction of Centrifugal Impeller with Its Diffuser Using Advanced Vortex Method

In this study, an advanced Lagrangian vortex-boundary element method is applied to simulate the unsteady impeller-diffuser interaction in a diffuser pump. Velocity calculations based on the Biot-Savart law reduce the need to grid large portions of the flow field and the calculation points are concentrated in the regions where vorticity is present. Lagrangian representation of the evolving vorticity field is well suited to moving boundaries. An integral pressure equation shows that pressure distribution can be estimated directly from the instantaneous velocity and vorticity field. The numerical results are compared with the experimental data and the comparisons show that the method used in this study can provide us insight into the complicated unsteady impeller-deffuser interaction phenomena in a diffuser pump.