Liquid droplet impingement erosion on groove roughness
Liquid droplet impingement erosion on groove roughness
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DOI：
10.1016/j.nucengdes.2018.02.021
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发表时间：
2018-04-15
影响因子：
1.7
通讯作者：
Fujisawa, Nobuyuki
中科院分区：
文献类型：
--
作者：
Fujisawa, Kei;Yamagata, Takayuki;Fujisawa, Nobuyuki
采用数值模拟和实验相结合的方法，对液滴撞击粗糙表面的冲蚀机理进行了研究。采用基于高分辨率有限体积法的两相全欧拉方法，对单凹槽粗糙度下的液滴碰撞进行了数值模拟，以了解液滴变形的演化过程和壁面压力分布。结果表明，与光滑表面上的LDI相似，第一次和第二次撞击都发生在液滴与壁面的第一次接触位置附近。最大的冲击发生在凹槽底部的第三次冲击，这是由液滴接触边缘产生的侧喷聚焦和液滴聚焦引起的。沟槽底部的最大壁压随沟槽粗糙度参数的增加而增加，该参数表示沟槽深度与液滴直径的几何比。在数值研究的基础上，利用扫描电子显微镜(SEM)对不同凹槽粗糙度参数的铝试件进行喷雾冲击后，观察了LDI对单个凹槽粗糙度的冲蚀行为。实验结果表明，大粗糙度沟槽的LDI磨损是从沟槽底部开始的，而小粗糙度沟槽的LDI侵蚀是从沟槽边缘和沟底开始的。这些实验结果与由数值结果得到的最大壁面压力分布有很好的相关性。
A study of erosion mechanism during the liquid droplet impingement (LDI) on a rough surface was conducted using both numerical simulation and experiments. The numerical simulation was carried out for the LDI on single groove roughness utilizing the two-phase full Eulerian approach based on the high-resolution finite volume method to understand the evolution of the droplet deformation and the wall pressure distribution. The numerical results for the LDI on a large groove roughness showed that the first and the second impacts occurred close to the first contact location of the droplet on the wall, which was similar to the LDI on a smooth surface. The largest impact occurred by the third impact at the groove bottom, which was caused by the side-jet focusing and droplet focusing generated from the contact edge of the droplet. It was also found that the maximum wall pressure at the groove bottom increased with the increase in the groove roughness parameter that represented the geometrical ratio of the groove depth to the droplet diameter. In addition to the numerical studies, the erosion behavior of LDI on single groove roughness was observed experimentally using a Scanning Electron Microscope (SEM) after spray jet impingement on an aluminum specimen with various groove roughness parameter. The experimental results showed that the LDI erosion on the large groove roughness started from the groove bottom, while the LDI erosion on the small groove roughness started from the groove edge and the groove bottom. These experimental findings are well correlated with the maximum wall pressure distributions obtained from the numerical results.