Numerical Prediction of the Influence of Particle Properties on the Hydraulic Performance and Wear of a Self-Priming Pump

In addressing the complexities associated with the conveyance of solid-liquid two-phase flow by a self-priming pump in field irrigation and drainage, this study numerically investigates the impact of three typical solid phase properties on the hydraulic performance of the pump, employing the Mixture multiphase flow model. Concurrently, utilizing the discrete phase model (DPM), the influence of operational speed and working condition flow rate on the wear of the flow passage components' walls is also numerically examined. The findings indicate that the order of significance for the impact on the hydraulic performance of the self-priming pump is as follows: the volume fraction of the solid phase, the hydraulic diameter of the particles, and the density of the solid particles. As these parameters increase, the corresponding relative decreases in head are 43.232%, 7.132%, and 5.541%, respectively, while the relative reductions in efficiency are 61.199%, 2.930%, and 9.805%, respectively. An increase in these parameters leads to a general trend of decline in the pump's hydraulic performance. Notably, while the volume fraction of the solid phase and the hydraulic diameter of the particles exhibit an enhancement in pressure capability, the density of the particles shows an inverse relationship with respect to pressure capacity. Additionally, it is observed that an increase in both rotational speed and flow rate at working conditions exacerbates the wear on the walls of all flow passage components. The degree of wear on the pressure side of the blades is markedly higher than that on the suction side. Furthermore, the wear on the pressure side of the blades is predominantly localized toward the middle-front section, specifically within 0 to 0.6 times the relative length of the blade, with the most severe wear concentrated at approximately 0.3 times the relative length of the blade, whereas the wear on the suction side is more pronounced in the middle-rear section, ranging from 0.4 to 1.0 times the relative length of the blade. This study represents the first investigation into the impact of solid particle properties in solid-liquid two-phase flows on the wear and hydraulic performance degradation of self-priming pumps during their operation. It provides theoretical guidance for the optimized design of self-priming pumps.