Research on the effects of different blade leading-edge geometries on the internal and external characteristics of centrifugal pumps

By studying the flow-field structures, turbulent kinetic energy (TKE), flow angle distribution, and pump performance of centrifugal pump impellers under different flow conditions, the influence mechanisms of the blade leading-edge geometry (elliptical, arc-shaped and circular) on energy loss in centrifugal pump impellers were studied. At large flow rate condition, the negative velocity gradient at the inlet caused by the squeezing effect is the main factor causing energy loss. The blunter the blade inlet shape, the greater the squeezing effect, and the closer the negative velocity gradient region is to the inlet, resulting in greater energy loss. For the low flow rate conditions, the large-scale vortex structures at the channel outlet are the flow structures that contributed most to the energy loss. The effect of the blade leading-edge geometry on the fluid increases gradually as it moves from inlet to outlet, and the sharper the blade inlet shape, the slower the fluid deviates from the blade in its subsequent development, suppressing the early formation of large-scale vortex structures, making their strength more dispersed at the channel outlet, and closer to the suction side, a lower vortex intensity, resulting in smaller energy loss of the impeller.