2020 年 48 巻 1 号 p. 47-52
Liquid droplet impingement erosion (LDI) occurs in fluid machinery on which many droplets impinge at high speed. In the process of LDI erosion, the material surface becomes completely roughened by erosion pits and these pits get locally deeper and deeper even though the droplets uniformly impinge on the material surface. In this study, to clarify the mechanism of erosion progressing in the form of locally deep depression, the numerical analysis of droplet impingement on the deep pit filled with water is conducted. From this result, the Rayleigh waves generated in the material by the droplet impingement propagate on the surface of the pit and interfere at the bottom. Therefore the stress generated at the bottom is larger than that of the droplet impingement. This may explain why the deep erosion pits are formed in liquid droplet impingement erosion even though the many droplets uniformly impinge on the entire material surface.
