Numerical Study on The Effect of Blade Leading Edge Rounding and Blade Number on Slurry Pump Performance

Centrifugal slurry pumps are essential for transporting solid–liquid mixtures in industries such as mining and thermal power generation. However, the presence of solid particles increases hydraulic losses, reduces efficiency, and accelerates component erosion, leading to lower performance compared to clean-water operation. Impeller geometry—particularly blade number and leading-edge shape—plays a critical role in mitigating these effects. This study numerically investigates the impact of blade number (Z = 3, 4, and 5) and rounded leading-edge geometry on the hydraulic performance of a centrifugal slurry pump. Three-dimensional simulations were performed using ANSYS CFX with an Eulerian–Eulerian multiphase approach and the standard k–? turbulence model to represent water and limestone particles (100 ?m diameter). The pump operated at 1250 rpm, with performance analyzed at solid concentrations of 10% and 20% and flow rates of 30–50 m³/h. Results show that increasing solid concentration reduces head and efficiency while increasing power consumption. The rounded leading edge improves inlet flow by minimizing separation and local turbulence. Among the tested configurations, the five-blade impeller (Z = 5) demonstrated the most stable internal flow, highest head and efficiency, and best erosion resistance. These findings align with existing literature, validating the numerical approach. This research provides valuable guidance for optimizing impeller design to enhance the efficiency and durability of slurry pumps operating at high solid concentrations.