论文标题
湍流喷气机的直接数值模拟：涡流 - 界面 - 表面表面互动
Direct numerical simulations of turbulent jets: vortex-interface-surfactant interactions
论文作者
论文摘要
我们研究了不溶性表面活性剂对湍流喷气机的时空演化的影响。我们使用三维数值模拟，并采用界面跟踪/级别测定方法来解释表面活性剂诱导的Marangoni应力。本研究以我们先前的工作为基础（Constante等，2021，J。流体机械，922，A6），在该研究中，我们在没有表面活性剂的情况下详细检查了涡旋表相互作用。对于广泛的韦伯和弹性数，获得了数值溶液，其中通过表面变形和表面活性剂诱导的Marangoni应力产生涡度产生。目前的工作首次证明了Marangoni应力的关键作用，这是表面活性剂浓度梯度所带来的，在形成相干，发夹样涡流结构中。这些结构对三维界面动力学的发展具有深远的影响。我们还介绍了在存在表面活性剂的存在下，对于一般，三维，两相流的机制，这些机制影响了循环的产量，并突出了Marangoni应力的主要贡献。
We study the effect of insoluble surfactants on the spatio-temporal evolution of turbulent jets. We use three-dimensional numerical simulations and employ an interface-tracking/level-set method that accounts for surfactant-induced Marangoni stresses. The present study builds on our previous work (Constante et al., 2021, J. Fluid Mech., 922, A6) in which we examined in detail the vortex-surface interaction in the absence of surfactants. Numerical solutions are obtained for a wide range of Weber and elasticity numbers in which vorticity production is generated by surface deformation and surfactant-induced Marangoni stresses. The present work demonstrates, for the first time, the crucial role of Marangoni stresses, brought about by surfactant concentration gradients, in the formation of coherent, hairpin-like vortex structures. These structures have a profound influence on the development of the three-dimensional interfacial dynamics. We also present theoretical expressions for the mechanisms that influence the rate of production of circulation in the presence of surfactants for a general, three-dimensional, two-phase flow and highlight the dominant contribution of Marangoni stresses.
