Impact of water drops on small targets
Impact of water drops on small targets
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DOI：
10.1063/1.1502663
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发表时间：
2002-09
影响因子：
4.6
通讯作者：
A. Rozhkov;B. Prunet-Foch;M. Vignes-Adler
中科院分区：
文献类型：
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作者：
A. Rozhkov;B. Prunet-Foch;M. Vignes-Adler
利用高速摄影技术对水滴与小目标的碰撞过程进行了实验研究。跌落冲击速度约为3.5 m/s。液滴直径在2.8-4.0 mm的范围内。靶是直径为3.9 mm的不锈钢盘。液滴扩散到目标之外，就像一个中心帽，周围是一个薄的、略呈圆锥形的薄片，边缘较厚。通过在目标附近设置一个小障碍物，在流动层中产生表面张力驱动的马赫波，这在形式上等价于气体动力学中常见的压缩性驱动的马赫波。从马赫角的测量中，可以获得一些流动参数的值作为时间的函数，这提供了对流动结构的洞察。液体以恒定的动量通量通过薄层从中心帽流到液体边缘。在此过程中，大部分液体聚集在板层的边缘和内部，成为亚稳态。
The collision of water drops against small targets was studied experimentally by means of a high-speed photography technique. The drop impact velocity was about 3.5 m/s. Drop diameters were in the range of 2.8–4.0 mm. The target was a stainless steel disk of 3.9 mm diameter. The drop spread beyond the target like a central cap surrounded by a thin, slightly conical lamella bounded by a thicker rim. By mounting a small obstacle near the target, surface-tension driven Mach waves in the flowing lamella were generated, which are formally equivalent to the familiar compressibility driven Mach waves in gas dynamics. From the measurement of the Mach angle, the values of some flow parameters could be obtained as functions of time, which provided insight into the flow structure. The liquid flowed from the central cap to the liquid rim through the thin lamella at constant momentum flux. At a certain stage of the process, most of the liquid accumulated in the rim and the internal part of the lamella became metastabl...