Energy loss characteristics of centrifugal pumps with blade perforation in clean and sediment-laden water

Most existing studies on multiphase flow and energy loss in centrifugal pumps adopt ideal intact geometric models, while real structural damages such as blade perforations induced by sediment abrasion are rarely taken into account. In this paper, numerical simulations under clean water and sediment-laden flow conditions are performed based on the discrete phase model, and a dedicated test stand is established to verify the simulation accuracy. Combined with the entropy production theory, the influences of perforation size on the head characteristics, total energy loss components, and radial distribution of energy loss within the impeller domain are quantitatively analyzed. The results show that blade perforations lead to a saddle-shaped head drop under low flow rates in clean water. When rp = 1.6, 2.4 and 3.2 mm, the maximum head drop within the saddle region reaches 1.79, 2.24, and 2.12 m, respectively. The average head reductions at low flow rates for the corresponding rp values are 0.27, 0.54, and 0.71 m, respectively. Radially distributed energy loss in the impeller domain rises first and then declines, with a local peak emerging in Region R4, where blade perforations are located and flow direction shifts simultaneously. As rp increases, the flow disorder near the blade leading edge and the coverage area of high entropy production rate (EPR) both expand; sediment particles further aggravate the flow instability and energy loss triggered by perforations.