Numerical Study on the Hysteresis Effect of Volute Pump with Stay Vanes Based on Vortex Dynamics

Abstract

The hysteresis effect of volute pump with stay vanes in the hump zone can aggravate the vibration and jumping of the units, which seriously threatens the unit’s safety and stable operation. The formation mechanism of the hysteresis effect in hump zone is analyzed by carrying out unsteady numerical simulation of the volute pump with stay vanes at medium-low specific speed based on vortex dynamics theory. The results show that hysteresis effect occurs in volute pump, the fluid inertia force in FID is smaller than that in FDD, and the fluid viscous force in FID is larger than that in FDD. The hysteresis effect is not only related to the Karman vortex generated by the flow separation of vane and guide vane, but also closely related to the stall vortex generated in the volute. This work may provide a guide way for the optimal design and stable operation of the volute pump with stay vanes.