Numerical simulation of the unsteady interaction of a centrifugal impeller with its volute casing

An accurate numerical analysis of the flows associated with impeller-volute configurations in turbomachinery can be extremely helpful in optimizing the performance of centrifugal turbomachinery. In the present study, without introducing the periodicity of the blade-to-blade stream, the two-dimensional unsteady features of the flows through a centrifugal impeller rotating in a volute casing of a pump are directly simulated by using direct vortex method. Results are presented in the form of the flow pattern of vortices, velocity vector, theoretical head coefficient of impeller and the unsteady hydraulic force on impeller. The results are compared with experimental data and the agreement is found to be good.