Influence of Meridian Shape on Screw-Type Centrifugal Pump Performance

A screw-type centrifugal pump with a wide flow passage has been widely used for drainage of rainwater as well as slurries and mud to avoid the flow passage blockage with the congestion of solids. Due to the complicated configuration of this pump, the design method of this pump has not been established yet. The authors succeeded in predicting the internal flow numerically by using our own grid-generation system and a commercial 3-D N-S code, TASCflow, as a solver. In this study, the internal flow has been predicted numerically at the design point on the five impellers with different hub cone shapes in order to clarify the influence of meridian shape on the pump performance. In particular, the relationships among the pump characteristics, the back flow at the blade pressure surface and the back flow from the volute casing to the impeller exit have been discussed in the numerical results on the velocity and pressure distributions.