The Effects of Impeller Blade Count on Centrifugal Pump Performance and Efficiency Under Different Operating Conditions: A Comparison of Numerical Prediction

Centrifugal pumps are widely used across various industries, such as water delivery, chemical processing, and HVAC systems, due to their efficiency and reliability in fluid handling. However, optimizing their performance remains a critical challenge, particularly in balancing head and efficiency under different operating conditions. This study explores the effect of impeller blade count on the performance and efficiency of centrifugal pumps using ANSYS 2024R1 computational fluid dynamics (CFD) simulations and polynomial regression models. Pumps with four, five, six, and seven blades were examined across flow rates (100–400 m³/h) and rotational speeds (1,500–4,500 rpm) to identify an optimal balance between performance and efficiency. The results reveal that increasing the blade count enhances fluid handling by reducing pressure fluctuations and creating more uniform pressure and velocity distributions. Among the configurations, the five-blade impeller at 2,500 rpm exhibited the best performance, achieving a head of 28.10 m and an efficiency of 91.9%. At higher speeds, efficiency peaked at specific blade counts but declined due to increased hydraulic losses. The seven-blade impeller produced the highest head of 64.1 m at 4,500 rpm, though efficiency dropped to 79.5%, highlighting the trade-off between head and efficiency. The regression models demonstrated high accuracy for each blade count. Notably, the four-blade configuration provided the most reliable predictions, with R² values of 0.9998 for the head and 0.9442 for efficiency. Similarly, the five-blade model showed strong performance, achieving R² values of 0.9972 for head and 0.7785 for efficiency. This study underscores the importance of selecting the optimal impeller blade count to balance performance and efficiency. Future work should investigate the influence of additional design parameters, such as blade angle and material composition, to further enhance centrifugal pump performance.