Numerical Investigations of a Single Stage Volute Pump in Viscous Operation

Abstract

CFD is used extensively to predict the performance of pumps and has proven to be a reliable tool for low viscosity fluids. Pump performance for high viscous operation is generally predicted from its water performance using empirical formulas, for example from the Hydraulic Institute standard ANSI/HI 9.6.7. However, the domain of application of these formulas is limited to certain pump sizes and configurations. The use of CFD as a tool for this task seems obvious, but not many studies on this topic have been presented so far. Several aspects of such a CFD calculation are not trivial, such as the effect of the viscous heating or the fact that the flow regime will not be fully turbulent in a large portion of the pump domain depending on the operating conditions and the viscosity. To provide some insight into the requirements for such CFD simulations, investigations of a single stage, double suction volute pump operating with water and oil were carried out and compared to measurement data covering a broad operating range. The results show that both the SST and intermittency turbulence models can predict the pump performance for high viscosity fluids well, despite local differences in flow regime prediction.