Deformation behavior of two droplets successively impinging obliquely on hot solid surface
Deformation behavior of two droplets successively impinging obliquely on hot solid surface
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DOI：
10.1016/j.expthermflusci.2016.10.009
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发表时间：
2017-02
影响因子：
3.2
通讯作者：
H. Fujimoto;Soushi Yoshimoto;Ken Takahashi;T. Hama;H. Takuda
中科院分区：
文献类型：
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作者：
H. Fujimoto;Soushi Yoshimoto;Ken Takahashi;T. Hama;H. Takuda
我们使用闪光摄影研究了两个液滴与热固体表面的连续倾斜碰撞。一对室温水滴垂直落下，依次撞击倾斜的光滑蓝宝石基板。液滴的直径约为 0.6 毫米，冲击速度在 1.6 至 2.1 m/s 之间变化。两个下落液滴中心之间的间距也在 0.8 到 1.5 毫米之间变化。基板相对于水平面倾斜 ⩽45°，其温度在 170 至 500 °C 之间变化。前导液滴撞击基底并在表面上向下滑动，随后尾随液滴相对于变形的前导液滴发生偏心碰撞。观察到“混合液体”的后续运动基本上是三维的。对于 200–300°C 的基材温度，由于自由表面沸腾蒸气泡的破裂，合并的液体会发生相当大的扭曲。在 500 °C 的基板温度下，液体运动大致呈线性对称。在液体中也观察到反弹现象。在不同条件下测量了液滴的停留时间，并将结果用于推导出用于预测该参数的表达式。
We investigated the successive oblique collision of two droplets with a hot solid surface using flash photography. A pair of water droplets at room temperature was vertically dropped to impact a tilted smooth sapphire substrate one after the other. The diameter of the droplets was approximately 0.6 mm and the impact velocity was varied between 1.6 and 2.1 m/s. The spacing between the centers of the two falling droplets was also varied between 0.8 and 1.5 mm. The substrate was titled at ⩽45° relative to the horizontal and its temperature was varied between 170 and 500 °C. The leading droplet impacted the substrate and slid downwards over the surface, and this was followed by the off-centered collision of the trailing droplet relative to the deformed leading droplet. The subsequent motion of the “combined liquid” was observed to be essentially three-dimensional. For substrate temperatures of 200–300 °C, the combined liquid was considerably distorted by the bursting of boiling vapor bubbles at the free surface. At a substrate temperature of 500 °C, the liquid motion was roughly linearly symmetric. Rebounding phenomena were also observed in the liquid. The residence time of the droplets was measured for different conditions, and the results were used to derive an expression for predicting this parameter.