Influence of trailing-edge thickness on energy dissipation and off-design energy conversion stability in centrifugal pumps

The influence of trailing-edge thickness on hydraulic performance, energy dissipation, and off-design energy conversion stability in a centrifugal pump was numerically investigated using computational fluid dynamics. Three trailing-edge thickness configurations (7, 11, and 15 mm) were evaluated under design and off-design operating conditions to examine their effects on internal flow behavior, hydraulic losses, turbulence dissipation, and entropy generation. The results showed that increasing trailing-edge thickness intensified blockage effects near the impeller outlet, leading to greater flow non-uniformity, stronger turbulence dissipation, and higher irreversible hydraulic losses. The 7 mm configuration provided the best overall hydraulic performance and maintained an efficiency of 72.31% at high-flow conditions, whereas the 15 mm configuration decreased to 61.76%. Entropy production analysis identified the trailing-edge wake region as the primary source of hydraulic loss and revealed that thicker trailing edges substantially amplified energy dissipation under off-design conditions. The maximum entropy amplification factor reached 2.13 under overload operation, indicating reduced energy conversion stability. These findings demonstrate that trailing-edge geometry plays a critical role in controlling hydraulic losses and energy conversion behavior, providing guidance for the design of more energy-efficient centrifugal pumps.