The effect of sand concentration on the erosion of materials by a slurry jet

Slurry erosion tests were performed to evaluate the effect of sand concentration on the erosion rate. By keeping the slurry velocity constant, different particle fluxes were obtained by varying the sand concentration in the slurry. The erosion tests were done with an erosion machine which gave a narrow slurry jet with a velocity of 17 m s −1. The slurry jet was always oriented toward the surface at a normal incidence angle. It was observed that the erosion rate decreased according to a power law of the sand concentration in the slurry. This effect can be attributed to the flow conditions near the surface giving rise to rebounding particles which protect the surface from incident particles. The scale of this effect also depends on the incidence angle of individual sand particles which are forced to deviate near the surface. Because there is a distribution of incidence angles near the surface, the relation between the protection effect and the incidence angle can explain partially the erosion profile of the eroded surface.