Numerical Calculation of Secondary Flow in Pump Volute and Circular Casings Using 3D Viscous Flow Techniques

摘要

The flow field in volute and circular casings interacting with a centrifugal impeller is obtained by numerical analysis. In the present study, effects of the volute and circular casings on the flow pattern have been investigated by successively combining a volute casing and a circular casing with a single centrifugal impeller. The numerical calculations are carried out with a multiple frame of reference to predict the flow field inside the entire impeller and casings. The impeller flow field is solved in a rotating frame and the flow field in the casings in a stationary frame. There are calculated: The static pressure and velocity in the casing and impeller, the static pressures and secondary velocity vectors at several cross- sectional planes of the casings. The calculations show that the curvature of the casings creates pressure gradients that cause vortices at cross-sectional planes of the casings.