Effects of Guide Vane Leading-Edge Profile on Hydraulic Performance and Interstage Erosion Characteristics of Deep-Sea Mining Pumps

The influence of guide-vane leading-edge profiles on interstage flow, particle transport, and erosion in multistage deep-sea mining pumps remains unclear. This study compares Convex, Linear, and Concave profiles in a two-stage pump using an Euler–Lagrange framework coupled with the Finnie erosion model. Hydraulic performance, pressure recovery, mainstream-flow organization, and particle transport were analysed at the design flow rate, whereas erosion characteristics were further evaluated over flow rates of 0.68Q–1.33Q and particle volume concentrations of 6–10%. At the design flow rate, the total head and overall hydraulic efficiency of the two-stage pump with the Concave profile reached 87.10 m and 53.32%, respectively. The Concave profile produced smoother pressure recovery, lower turbulent kinetic energy, and mainstream-flow ratios of 63.3% and 69.0% downstream of the first- and second-stage guide vanes, respectively. In the first-stage leading-edge region, its average particle mass concentration was 6.42% and 33.84% lower than those of the Convex and Linear profiles, respectively, demonstrating that the Concave profile effectively reduced particle accumulation near the guide-vane leading edge. In contrast, the Convex profile exhibited interstage erosion amplification, whereas erosion for the Linear profile was concentrated mainly in the first stage. Erosion increased with both flow rate and particle concentration for all profiles. Overall, the Concave profile provided the best balance among hydraulic performance, reduced particle accumulation, and predicted erosion resistance.