Archard Model for Wear Characteristics of Slurry Pump Impellers in Non-Newtonian Fluids

Deep-sea drilling relies on mud lifting systems, in which slurry pumps are critical components. Unlike conventional deep-water pumps, slurry pumps transport non-Newtonian fluids containing solid particles, resulting in severe internal wear of flow-passing components. In this study, the CFD-DEM coupling method was employed to establish a solid-liquid two-phase flow model under non-Newtonian conditions. The flow characteristics of non-Newtonian fluids were investigated, and an Archard wear model was developed to analyze the wear mechanisms of slurry pump components. The inlet water flow velocity was set to 3.53 m/s, the rotational speed was fixed at 2950 rpm, and the particle concentration was maintained at 10%. Wear resistance experiments with different surface treatments were further conducted to validate the numerical model. The results indicate that severe wear on the impeller blades mainly occurs at the leading-edge pressure surface and trailing edge. On the rear shroud, serious wear appears in the annular region near the shaft and at the junction with the blade leading edge. On the front shroud, wear is mainly concentrated between the blade pressure surface and impeller outlet, while the front shroud exhibits the lowest overall wear. Quantitative comparison between simulation and experiments shows good agreement in wear distribution trends. Plasma nitriding was found unsuitable for slurry pump applications, increasing mass loss by 3.3%, whereas tungsten carbide HVOF spraying effectively improved wear resistance and reduced mass loss by 20.8%. Straight blade configurations readily induce leading-edge wear, flow separation, and vortex structures, thereby shortening service life. The high particle velocity near the blade leading edge is identified as the primary reason for severe local wear in this region.