Theoretical study on the efficiency of axial flow submersible pumps considering the influence of diffuser cone angle

Abstract

This study presents a combined theoretical and experimental investigation into how the diffuser cone angle affects the hydraulic efficiency of submersible axial-flow pumps. Unlike conventional axial-flow designs, submersible configurations often require larger diffuser expansion angles due to structural constraints, potentially causing severe flow separation and energy losses. A theoretical model is proposed to quantify head loss due to cone angle variation, based on boundary layer theory and diffuser geometry. This model is validated through experimental testing on a full-scale HTCĐ 3000-3 pump under varying diffuser cone angles (0°, 42°, 60°). Results show that hydraulic efficiency (η_hyd) drops from 85.0% at 0° to 67% at 60°, with theoretical predictions deviating from experimental results by less than 2.3%. The findings highlight the critical role of diffuser geometry in optimizing pump design for high-flow, compact systems, offering a reliable tool for energy-efficient design in submersible pumping applications.