Numerical simulation of unsteady flow in a multistage centrifugal pump using sliding mesh technique

In this work, three-dimensional, unsteady Reynolds-Averaged Navier-Stokes (RANS) equations with standard k-epsilon turbulence models are solved by employing sliding mesh technique within an entire stage of a multistage diffuser pump to investigate transient flow field and pressure fluctuations due to the interaction between impeller and diffuser vanes. Sliding mesh calculation is carried out as the impeller zones slide (i.e., rotate) relative to diffuser zone along the grid interface in discrete time steps. The complicated time-periodic and spatial-periodic characteristics as well as rotor-stator interaction phenomena inside the pump stage arc simulated and analysed to understand dynamic variation of the interior flow field and interference and finally to aim at optimal design.