Numerical Investigation of Entropy Generation Mechanism for Non‐Newtonian Fluids in Centrifugal Pumps

Centrifugal pumps are widely utilized in petrochemical production. When conveying such media, their special non‐Newtonian rheological properties intensify energy losses within the pump, leading to performance degradation. This study investigates the energy dissipation mechanisms in centrifugal pumps handling non‐Newtonian fluids using entropy generation analysis under various flow conditions. The results show that the local entropy generation loss mainly occurs in the volute diffuser‐adjacent impeller passages and volute inlet section, with particular severity at partial load conditions. The turbulent entropy generation loss is the main mechanism of local entropy generation losses, accounting for over 98%, while the viscous entropy generation loss accounts for less than 2%. Flow field analysis shows that the adverse pressure gradient generated by the volute diffuser induces backflow and vortex in both the impeller domain and the volute domain. The shear‐thinning effect produced by these phenomena promotes the turbulent pulsation of the fluid, leading to local entropy generation loss. The shearing effect of the backflow on the impeller wall surface is an important factor contributing to the formation of the wall entropy generation loss. This study reveals the energy loss mechanism of shear‐thinning non‐Newtonian fluids in centrifugal pumps, providing references for pump design and optimization.