The dynamics of ligaments retracting under the action of surface tension occurs in a multitude of natural and industrial applications; these include inkjet printing and atomization. We perform direct, fully three-dimensional, two-phase numerical simulations of the retracting process over a range of system parameters that account for surfactant solubility, sorption kinetics, and Marangoni stresses. Our results indicate that the presence of surfactant inhibits the “end-pinching” mechanism and promotes neck reopening through Marangoni-flow; this is induced by the formation of surfactant concentration gradients that drive flow-reversal toward the neck. The vortical structures associated with this flow are also analyzed in detail. We also show that these Marangoni stresses lead to interfacial rigidification, observed through a reduction of the retraction velocity and ligament kinetic energy.

中文翻译：

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在中等Ohnesorge数下缩满表面活性剂的韧带的动力学

韧带在表面张力的作用下缩回的动力学发生在许多自然和工业应用中。这些包括喷墨打印和雾化。我们在考虑表面活性剂溶解度，吸附动力学和Marangoni应力的一系列系统参数上执行缩回过程的直接，完整的二维两阶段数值模拟。我们的结果表明，表面活性剂的存在抑制了“末端捏”机制，并通过Marangoni流动促进了颈部的重新张开。这是由于表面活性剂浓度梯度的形成而引起的，该表面活性剂浓度梯度带动流向颈部流动。还详细分析了与此流相关的旋涡结构。我们还表明，这些Marangoni应力会导致界面硬化，