Rain erosion mechanism on a leading-edge half cylinder

Abstract

In this short communication, the rain erosion mechanism on a leading-edge half cylinder was investigated both experimentally and numerically focusing on the influence of leading-edge curvature. A scale-model experiment was carried out in a spray-jet erosion test facility for aluminum specimens of half cylinders with various leading-edge curvatures d/R, defined by the droplet diameter d to the radius of curvature R, ranging from d/R = 0.02 to 0.13. The measurements of erosion volume loss of the half cylinder and the surface observation by scanning electron microscope were performed to understand the influence of leading-edge curvature on the erosion characteristics. It was found that the erosion rate of the specimen highly increases with an increased leading-edge curvature, which is associated with the earlier erosion initiation of pit formation on the surface. To understand the curvature effect on the leading-edge erosion of the half cylinder, the numerical simulation of the liquid sheet impacting on the leading edge was carried out and the liquid-film behavior was studied. It was found that the film thickness on the leading-edge half cylinder decreases faster on larger curvature than that on smaller curvature, which agrees with an increased erosion rate at larger curvature in the present experiment.