Threshold for discretely self-similar satellite drop formation from a retracting liquid cone
Threshold for discretely self-similar satellite drop formation from a retracting liquid cone
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DOI：
10.1103/physrevfluids.3.104002
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发表时间：
2018-10
影响因子：
2.7
通讯作者：
C. Brasz;A. Berny;J. Bird
中科院分区：
文献类型：
--
作者：
C. Brasz;A. Berny;J. Bird
从气泡引发的大气气溶胶到喷墨打印，预测从液体喷射中脱落的液滴的大小非常重要。当细细的液体线形成并破裂的速度比其末端完全收缩的速度快时，就会形成更小的卫星液滴，这使这些预测变得复杂。这一过程通常是通过用相对于圆柱体直径较小的振幅扰动圆柱形液体螺纹来模拟的。然而，在掐断过程的早期，液体线的末端是锥形的，并且缺乏一个特征长度尺度，从而无法将有限扰动归一化。在这里，我们数值模拟了几乎不粘的圆锥形细丝的收缩，并引入自相似的扰动来驱动系统进入一个离散的自相似的收缩，可以在不偏置特定长度尺度的情况下实现破裂。我们发现，对于大多数锥角，扰动幅度必须超过阈值才能形成卫星滴。我们证明了这个临界扰动幅度取决于锥角，并且可以通过基于初始扰动锥的静态稳定性的参数准确地预测。
Predicting the size of droplets that pinch off from a liquid jet is important to applications ranging from bubble-initiated atmospheric aerosols to inkjet printing. These predictions are complicated by smaller satellite drops that form when a thin liquid thread develops and breaks up faster than its ends fully retract. Typically this process is modeled by perturbing a cylindrical liquid thread with an amplitude that is small relative to the cylinder diameter. Yet early on in the pinch-off process, the ends of the liquid thread are conical and lack a characteristic length scale from which to normalize a finite perturbation. Here we numerically simulate the retraction of nearly-inviscid conical filaments and introduce self-similar perturbations to drive the system into a discretely self-similar retraction that can enable breakup without biasing a particular length scale. We find that for most cone angles, the perturbation amplitude must exceed a threshold for satellite drops to form. We show that this critical perturbation amplitude depends on the cone angle and can be accurately predicted by an argument based on the static stability of the initial perturbed cone.