Investigation of Inducer Geometry Variations on Centrifugal Pump Hydraulic Performance: Numerical Approach

Abstract

Efficient suction performance and cavitation resistance are critical challenges in high-speed, low-pressure centrifugal pumps, and inducers, which are helical axial-flow components positioned upstream of pump impellers, play a pivotal role in addressing these challenges. This study evaluates the influence of inducer geometric parameters on impeller inlet pressure to identify configurations that enhance suction performance and reduce cavitation risk in centrifugal pumps. Experimentally validated three-dimensional numerical simulations were conducted to investigate the effects of hub-to-tip diameter ratio, blade angle, and blade number, which were systematically varied to examine their impact on pressure recovery and flow stability. Results show that decreasing the hub-to-tip ratio from 0.59 to 0.33 increased the average static pressure ratio at the impeller inlet from 1.12 to 1.38, corresponding to a 14%–23% improvement in suction performance. Increasing the blade angle from 15° to 30° enhanced local inlet pressure by 6%–30%, raising the pressure ratio from 1.10 to 1.43, while increasing the blade number from 2 to 4 yielded a 17%–23% pressure rise, with the pressure ratio increasing from 1.18 to 1.40. The optimal configuration with a hub-to-tip ratio of 0.33, blade angle of 30°, and four blades reduced the low-pressure region near the hub by approximately 28%, indicating improved cavitation resistance. Flow visualization using meridional streamlines and static pressure contours confirmed smoother acceleration and reduced recirculation for the optimized design. These findings provide quantitative insights into inducer geometry optimization and offer guidance for enhancing suction capability and designing high-performance centrifugal pumps.