Impact of Interface Model on Simulation Results of a Radial Pump at Part Load and Shut-Off Conditions

Abstract

Computational Fluid Dynamics (CFD) is a well-known tool for predicting and analyzing performance in a variety of engineering branches, including turbomachinery, allowing engineers to partially replace physical experiments with their virtual analog. Nevertheless, numerical analysis should be used carefully regarding possible deviation between simulated and experimental results due to multiple reasons (including but not limited to applied simplifications in the numerical model). These deviations usually have their minima close to the Best Efficiency Point (BEP). The paper deals with analyzing the outcome of steady-state simulations for a radial pump at strong part load and shut-off conditions by switching between three simulation types (steady-state with mixing plane, steady-state with frozen rotor, transient with sliding mesh). A comparison of velocity profiles on the interface surfaces is made, showing how the chosen interface model affects the structures being formed at part load conditions. These effects show particular impact on performance parameters (first of all, head production), which is discussed in the paper. The information provided could be helpful for adjusting the simulation parameters and finding an appropriate compromise between simulation reliability and demand for computational time thereby.