Computational Fluid Dynamics Analysis of a Centrifugal Pump Based on Solid-Liquid Two-Phase Turbulence.

Abstract

To analyze the internal flow field and flow characteristics within the impeller of a centrifugal pump handling solid-liquid two-phase flow, FLUENT software was applied to numerically simulate the solid-liquid two-phase flow in two different impeller designs. Using the Re-Normalization Group (RNG) turbulence model, the velocity and pressure fields were compared and the performance of the solid-liquid centrifugal pump was predicted. The results showed that the numerical simulation closely matched experimental data, proving the feasibility and validity of the solid-liquid two-phase turbulence model used in this study, with considerable potential for engineering applications. The average pressure distribution across the flow channels of both impellers was similar. For the five-blade pump, when the particle size of <i>d</i> _s ranges from 0.2 to 2 mm, the pump head decreases by 4.31%. While for the particle size of <i>d</i> _s, as it varies from 1 to 4 mm, the pump head drops by 2.23%, but the head of the composite-blade impeller was higher than that of the five-blade impeller. When the volume fraction of solid particles remained constant, the efficiency of the pumps with different blade parameters showed significant variation with changes in particle size. When the particle size increases, the efficiency of the composite-blade pump decreases slowly. However, for the five-blade pump, when the particle size <i>d</i> _s < 1 mm, its efficiency drops rapidly as the particle size increases. Neither pump could maintain relatively high efficiency under all operating conditions. Therefore, for solid-liquid two-phase centrifugal pumps, it is crucial to design and operate the pumps according to the specific properties of the slurry.