论文标题
锥形关注：从崩溃的掉落陨石坑中奇异喷射机制
Conical-focusing: Mechanism for singular jetting from collapsing drop-impact craters
论文作者
论文摘要
快速微型喷气机可以从液体池中出来，从掉落的火山口的反弹中，或者当气泡在其表面爆裂时。最快的喷气机是最狭窄的，是海洋和一杯香槟，对气候和嗅觉的重要性的来源。当在降低的环境压力下，最大速度为137 $ \ pm $ 4 m/s，直径为12 $ $ m的直径为12 $ $ m的速度，当火山口底部的小凹痕形式并弹起而无需捏合一个小气泡时，就会产生。这种酒窝的反弹纯粹是惯性的，但对初始条件高度敏感。高分辨率的数值模拟揭示了一种新的聚焦机构，该机制在收敛的圆锥形通道内驱动最快的射流，其中夹带的空气表可在圆锥体收敛流到射流的外部边界处有效滑动。这种配置绕过了射流速度的任何粘性切口，并解释了现象的详细实验中观察到的极端灵敏度。
Fast microjets can emerge out of liquid pools from the rebounding of drop-impact craters, or when a bubble bursts at it surface. The fastest jets are the narrowest and are a source of aerosols both from the ocean and a glass of champagne, of importance to climate and the olfactory senses. The most singular jets, which have a maximum velocity of 137$\pm$4 m/s and diameter of 12 $μ$m under reduced ambient pressure, are produced when a small dimple forms at the crater bottom and rebounds without pinching off a small bubble. The rebounding of this dimple is purely inertial but highly sensitive on initial conditions. High-resolution numerical simulations reveal a new focusing mechanism, which drives the fastest jet within a converging conical channel, where an entrained air-sheet provides effective slip at the outer boundary of the conically converging flow into the jet. This configuration bypasses any viscous cut-off of the jetting speed and explains the extreme sensitivity observed in detailed experiments of the phenomenon.
