Performance mapping of modular annular jet pumps for slurry transport—A mixture model approach

Abstract

This study develops a CFD-based performance-mapping framework for modular Annular Jet Pumps under slurry transport conditions, focusing on how geometric and operating parameters govern hydraulic performance, turbulence, and erosion risk. Using a validated Mixture Model coupled with the realizable k–ε turbulence closure, detailed simulations were performed to quantify how these performance indicators vary with Reynolds number, nozzle convergence angle (21°–27°), dispersed phase volume fraction (0–0.4), and sand particle size (200 μm to 1000 μm). A validated mixture-model framework, benchmarked against existing literature with prediction errors below 2 %, is applied to systematically evaluate the performance indicators, including Pressure Gradient, Wall Shear Stress, Specific Energy Consumption and their normalised counterparts. Results demonstrate that Reynolds number increases from 0.8 × 10⁵ to 1.6 × 10⁵ as primary flow rate and nozzle convergence angle rise, strengthening entrainment but sharply elevating Pressure Gradient (0.6–2.0 kPa/m), Specific Energy Consumption (0.35–1.2 J/kg), and WSS (8–25 Pa). Solid concentration strongly modulates performance as increasing the dispersed phase volume fraction from 0.1 to 0.4 enhances suspension and reduces Normalised Specific Energy Consumption by nearly 60 % but also intensifies near-wall stresses and erosion potential, with Normalized Wall Shear Stress nearly doubling. Particle size effects are moderate, though larger particles (up to 1000 μm) induce localized slip and settling tendencies that degrade hydraulic stability. The resulting multi-dimensional performance maps identify operational windows where suction performance is maximized while Specific Energy Consumption and Wall Shear Stress remain within sustainable limits, offering predictive tools for balancing efficiency, durability, and throughput. Unlike prior studies, which were limited to isolated metrics, this work integrates normalized performance indicators with turbulence-resolved CFD to deliver the first comprehensive mapping framework for modular Annular Jet Pumps, bridging fundamental modeling and actionable design guidelines for mining, dredging, and hydraulic conveying industries.