Jet formation during the gas penetration through a thin liquid layer
Jet formation during the gas penetration through a thin liquid layer
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气体渗透薄液层时形成射流
DOI：
10.1063/1.5066593
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发表时间：
2019-01
影响因子：
4.6
通讯作者：
Fu Xin
中科院分区：
文献类型：
--
作者：
Li Mingbo;Hu Liang;Xu Hanghang;Chen Weny;Xie Haibo;Fu Xin
到达液体表面的自由气泡通常会破裂，然后形成喷射液滴的液体射流。虽然气泡介导的射流是一个被广泛研究的话题，但很少有研究涉及气泡增长产生的射流。在这里，我们报告并描述了一种新的现象，称为周期性气泡破裂，当连续的气体流穿透薄的液体层时，就会发生这种现象。该过程复杂，具有一定的特征频率，可分为鼓泡、空腔塌陷和射流三个阶段。结果表明，增大液层厚度和气体流速可使气泡增大。然而，这种影响与孔直径密切相关，并推导出气泡破裂半径的标度规律。随后，我们证明了崩塌空腔具有形状相似性，并推导出锥形空腔的掐断高度和开口角与气泡破裂半径和液层厚度的关系。这使我们能够解开三种不同的掐颈机制在掐断中发挥作用。因此，重力塑造了空腔，并参与了毛细波的选择，从而强烈地调节了射流的形成。随着层厚的增加，射流首先变得又大又小，然后变得又薄又高，分离出更多更小的液滴。我们给出了射流速度的一个简单的标度律，它与液体层厚度的1/2次方有关。最后，根据最初的韦伯数和邦德数，建立了射流分裂和不分裂的相图。
A free bubble reaching the liquid surface usually bursts and then forms a liquid jet with drops ejected. While bubble-mediated jetting is a topic widely studied, few investigations deal with the jet produced by a growing bubble. Here, we report and characterize a novel phenomenon, named periodic bubbling-bursting, that can develop when a continuous stream of gas penetrates through a thin liquid layer. This behavior is complex with a characteristic frequency and can be divided into three stages from bubbling to cavity collapse and jetting. We show that increasing the liquid layer thickness and gas velocity leads to a larger bubble. However, the effect is strongly coupled with the orifice diameter and a scaling law of the bubble rupture radius is derived. Subsequently, we demonstrate that the collapsing cavities exhibit shape similarity and deduce the dependence of pinch-off height and opening angle of the conical cavity on the bubble rupture radius and liquid layer thickness. This enables us to disentangle three different neck-pinching mechanisms at play in pinch-off. Accordingly, gravity shapes the cavity and participates in the capillary wave selection that strongly modulates the jet formation. With increasing layer thickness, the jet first becomes fat and small and then ends up thinner and higher, detaching more and smaller droplets. We present a simple scaling law for the jet velocity which involves the liquid layer thickness to the power 1/2. Finally, a phase diagram for jet breakup and no breakup is built with respect to the initial Weber and Bond numbers.
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影响因子：
4.6
作者：
Ying Shen;Liang Hu;Wen-yu Chen;Xin Fu
通讯作者：
Ying Shen;Liang Hu;Wen-yu Chen;Xin Fu
影响因子：
4.6
作者：
Tianqi Guo;M. Rau;P. Vlachos;S. Garimella
通讯作者：
Tianqi Guo;M. Rau;P. Vlachos;S. Garimella
影响因子：
3.8
作者：
Jianfu Zhao;W. Hu
通讯作者：
Jianfu Zhao;W. Hu
DOI：
10.3402/tellusa.v9i2.9094
发表时间：
1957-05
期刊：
Tellus A
影响因子：
--
作者：
D. Blanchard;A. H. Woodcock
通讯作者：
D. Blanchard;A. H. Woodcock
影响因子：
64.8
作者：
Bird, James C.;de Ruiter, Rielle;Stone, Howard A.
通讯作者：
Stone, Howard A.