Study on energy dissipation effect of solid-liquid flow in centrifugal pump based on improved four-way coupling method

In the solid-liquid two-phase flow within the centrifugal pump, due to the coupling effect of solid and liquid, the performance of the centrifugal pump is significantly reduced, resulting in a large amount of energy loss. To reduce energy losses in solid-liquid flow, the impact of particle density on energy losses within a prototypical centrifugal pump has been investigated, based on an improved four-way coupling method. First, the improvement strategy of the four-way coupling method and the pump model parameters are introduced. Then, the effectiveness of the improved method is validated. Finally, the energy loss mechanisms under different particle density conditions are explored. The study found that incorporating the turbulence dissipation caused by particle dispersion forces and the velocity field reconstruction method can effectively improve the simulation accuracy of the four-way coupling method. Energy loss within the centrifugal pump mainly occurs in the volute region. Under three different particle densities, for every 700 kg/m³ increase in density, the turbulence entropy production dissipation in the volute region increases by 7.03 % and 10.87 %, respectively. Turbulent entropy generation dissipation dominates within the pump, and at different axial sections of the blade height, the turbulent entropy generation loss increases with the spanwise value. Entropy generation losses in the volute region are primarily concentrated in the tongue, wall surfaces, and the impeller wake area. The turbulent kinetic energy within the volute passage exhibits an inverted “S” shape variation along the direction of increasing cross-sectional area. The findings provide valuable insights for reducing energy dissipation in the solid-liquid flow within centrifugal pumps.