Numerical analysis of liquid droplet impingement on rough material surface with water pool

29th IAHR Symposium on Hydraulic Machinery and Systems

Sasaki, Hirotoshi^1 ; Iga, Yuka^1

Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai

980-8577, Japan^1

关键词: Analysis of liquids;    Cavitation bubble;    Collapse pressure;    Coupled numerical methods;    Droplet impingement;    Equivalent stress;    Liquid droplets;    Material surface;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/6/062053/pdf
DOI  :  10.1088/1755-1315/240/6/062053

来源: IOP

【 摘 要 】

Liquid droplet impingement erosion occurs at the elbows in steam pipes where droplets impinge at high speed. In the actual pipe wall which numerous droplets always impinge, it is predicted that both a liquid lm exists on a pipe wall surface and, on the other hand, this surface is also eroded by repeated droplet impingement. Therefore, the liquid lm and roughness on the material surfaces are considered to exist mixed on the actual impinged point of droplets. In this study, by using an in-house uid/material two-way coupled numerical method that considers re ection and transmission on the uid/material interface, the numerical analysis of the phenomenon of liquid droplet impingement on a pitted surface with a water pool is conducted. From the analysis results, the impinged pressure at the moment of impingement is alleviated by a water pool. However, as the cavitation bubbles are generated in the bottom and top of the droplet and then the cavitation bubble of the bottom side collapses, the collapse pressure which greatly exceeds the pressure of the droplet impingement occurs, and the equivalent stress also increases greatly there. Therefore, this analysis result may indicate one reason why the erosion progresses deeply at the pit part in an actual pipe wall thinning.