Role of all jet drops in mass transfer from bursting bubbles
Role of all jet drops in mass transfer from bursting bubbles
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DOI：
10.1103/physrevfluids.5.033605
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发表时间：
2020-03-10
影响因子：
2.7
通讯作者：
Popinet, Stephane
中科院分区：
文献类型：
--
作者：
Berny, Alexis;Deike, Luc;Popinet, Stephane
当一个气泡在液体表面破裂时，它会产生一个射流，这个射流可能会破裂并产生喷射液滴。从香槟中的气泡到海洋/大气的相互作用，这一现象由于其多种应用而激发了许多研究。我们通过直接数值模拟轴对称两相液气Navier-Stokes方程来模拟单个气泡的破裂。我们描述了所有喷射液滴的数量、大小和速度，对于广泛的控制参数，定义为无量纲数，比较毛细力和粘性力的拉普拉斯数和比较重力和毛细力的Bond数。喷射液滴的总垂直动量显示遵循一个简单的缩放关系，主要依赖于拉普拉斯数。通过一个简单的蒸发模型，结合数值计算得到的动力学结果表明，由于爆裂事件产生的所有喷射液滴（最多14个）都是蒸发水量的一部分，因此必须考虑它们。得到了蒸发水量随气泡大小和流体性质的函数的简单标度关系。这种关系是朝着建立海洋-大气水汽通量的物理模型迈出的重要一步，该模型是由表面破裂的气泡控制的。
When a bubble bursts at the surface of a liquid, it creates a jet that may break up and produce jet droplets. This phenomenon has motivated numerous studies due to its multiple applications, from bubbles in a glass of champagne to ocean/atmosphere interactions. We simulate the bursting of a single bubble by direct numerical simulations of the axisymmetric two-phase liquid-gas Navier-Stokes equations. We describe the number, size, and velocity of all the ejected droplets, for a wide range of control parameters, defined as nondimensional numbers, the Laplace number which compares capillary and viscous forces and the Bond number which compares gravity and capillarity. The total vertical momentum of the ejected droplets is shown to follow a simple scaling relationship with a primary dependency on the Laplace number. Through a simple evaporation model, coupled with the dynamics obtained numerically, it is shown that all the jet droplets (up to 14) produced by the bursting event must be taken into account as they all contribute to the total amount of evaporated water. A simple scaling relationship is obtained for the total amount of evaporated water as a function of the bubble size and fluid properties. This relationship is an important step toward building a physics-based model of the ocean-atmosphere water vapor fluxes controlled by bubbles bursting at the surface.