Vortex dynamics analysis of an energy loss mechanism in a centrifugal pump impeller

Centrifugal pumps play a vital role in industrial production, particularly for the transportation of viscous liquids, where they often incur significant energy losses. This study investigates the energy loss mechanisms in centrifugal pump impellers, focusing on the dynamics of vortices under varying viscosities and rotational speeds through numerical simulation. The proportion and distribution of entropy production under different viscosities and rotational speeds are discussed, and the influence of different terms of the vorticity transport equation on vorticity changes is analyzed. The results show that turbulent dissipation entropy production is the main entropy production at low viscosities. As the viscosity increases, the proportion of wall entropy production rises and becomes the main source of energy loss in the pump. Under high rotating speed condition, the Coriolis force source term is the main reason for vorticity changes. As the viscosity increases, the Coriolis force source term decreases sharply, and the relative vortex stretching term also decreases. Meanwhile, the viscosity diffusion term increases and becomes the main reason for the reduction of unstable flow in the impeller of a centrifugal pump for high-viscosity fluid media. This study combines the vorticity transport equation with entropy production analysis to analyze the energy conversion process and loss generation mechanism in a centrifugal pump, and deeply explore the relationship between the vorticity field and energy loss in the impeller. It has theoretical and practical significance for improving the efficiency of centrifugal pumps in transporting viscous fluids and providing support for related designs.