Plane-wise multiphase flow and turbulence analysis in a modular annular jet pump for slurry transport applications—A mixture model approach

Abstract

This study presents a detailed plane-wise analysis of multiphase flow and turbulence behavior in a modular annular jet pump (AJP) for slurry transport applications. A two-dimensional axisymmetric CFD model is developed using the mixture model with the Realizable k-ε turbulence model. Water is used as the primary fluid, and slurry comprising water with 20 % sand (by volume) as the secondary fluid. The primary flow rate is varied from 6 to 11 m3/h, while the interphase slip is modeled using the Schiller–Naumann drag correlation. A structured mapped mesh with an average element quality of 0.9815, average skewness of 0.0185, and estimated orthogonal quality of 0.98 is employed, with a target y+ value of 50. Standard wall functions are used for accurate near-wall turbulence treatment. Mesh independence is confirmed through a sensitivity analysis, showing a maximum deviation of under 1.5 % in key design parameters. The model is validated through agreement with established literature. The study evaluates flow parameters (pressure, velocity, volume fraction, slip velocity) and turbulence characteristics (turbulent kinetic energy, dissipation rate, and turbulent viscosity) at the AJP inlet, throat center, and outlet. Additionally, wall shear stress and drag coefficients are investigated along the converging, throat, and diverging walls. Results reveal peak turbulence intensity and phase interaction near the throat, with pronounced transformation of flow structures along the axial direction. The modular design enables geometry changes without full reprinting, offering a flexible and cost-effective approach. Findings provide valuable insights for optimizing AJPs toward higher energy efficiency and stable multiphase transport.