Large Eddy Simulation of a Regenerative Pump

Large eddy simulation (LES) of a regenerative pump is carried out to insightfully analyse the vortical flow driven by the impeller. The driven mechanism yields high heads in circumferential travel of pumped fluid through the impeller’s blades and the annular open side channel. The Reynolds averaged Navier-Stokes (RANS) is employed to figure out a compromise among imperative geometrical parameters for an averaged uniform outflow. The symmetric side channel reduces the unsteadiness of the outflow in the streamlined outlet. On the other hand, the well-resolved LES result, which is validated against experimental measurement, elaborates the flow field characteristics such as coherent structures generated from the fluid axially entering the inter-blade channel close to the hub and being radially discharged from the channel. This recirculation decides about the mixing rate of pump, the turbulent intensity and the structure size which are of particular interests. The flow entering the side channel transfers the added angular momentum to the peripheral flow in the circumferential direction and into the following inter-blade channels. This repetitive (regenerative) helical path generates high heads at relatively low specific speeds in a single impeller stage.