Study of the Rotor-Stator Interaction Phenomenon in a Centrifugal Pump

Abstract

During operation of a turbomachine Rotor Stator Interaction phenomenon, RSI, appears in several cases. This phenomenon induces pressure fluctuations and it is closely related to the unsteadiness in the flow, which is highly turbulent, and due to the relative movements between moving and fixed parts of the machine. The induced pressure pulses and its oscillation frequencies could induce Flow-Structure Interactions, FSI, causing fatigue damages in the blades under certain conditions. The importance of the knowledge of the machine behavior under operation conditions that induces critical pressure pulses is of paramount interest, because the lifetime of the machine could be enhanced if this situation is suppressed. Computational Fluid Dynamics, CFD, is a powerful tool for studying the complex behavior of the flow that induces the RSI phenomena inside the machine, due to experimental options for studying this phenomenon are very expensive in these cases. But in some cases, due to the intrinsic unsteady nature of the RSI, the computational costs are very high if more sophisticated options are used (e.g., Large Eddy Simulations or Detached Eddy Simulations), becoming a prohibitive option for industrial flow modeling. In order to maintain the computational costs in an affordable level, in this work the main goal is to model the unsteady behavior by using a recently developed turbulence modeling option, related to the ScaleAdaptative-Simulation, SAS, applied to Eddy Viscosity Models, EVM. This option was selected, for searching an optimized use of the computational resources without loss accuracy in the details of the flow inside the machine.