Through an Hamiltonian action we write down the system of equations of motions for a mixture of thermocapillary fluids under the assumption that the internal energy is a function not only of the gradient of the densities but also of the gradient of the entropies of each component. A Lagrangian associated with the kinetic energy and the internal energy allows to obtain the equations of momentum for each component and for the barycentric motion of the mixture. We obtain also the balance of energy and we prove that the equations are compatible with the second law of thermodynamics. Though the system is of parabolic type, we prove that there exist two tangential acceleration waves that characterize the interfacial motion. The dependence of the internal energy of the entropy gradients is mandatory for the existence of this kind of waves. The differential system is non-linear but the waves propagate without distortion due to the fact that they are linearly degenerate (exceptional waves).
Interface Fluctuations in a Turbulent Binary Fluid using Data-Driven Methods
Center for Condensed Matter Theory, Indian Institute of Science（印度科学学院凝聚态理论中心）；Centre for Ocean, River, Atmosphere and Land Sciences, Indian Institute of Technology, Kharagpur（印度理工学院卡拉格普尔分校海洋、河流、大气与陆地科学中心）
Interfacial standing wave-patterns disentangle dilatational and shear surface viscous effects
Imperial College London（帝国理工学院）；Abdullah Al Salem University（阿卜杜拉·萨勒姆大学）；Université Paris Saclay（巴黎萨克雷大学）；Hongik University（弘益大学）；University of Cambridge（剑桥大学）
A conservative coupling method of sharp-interface and multi-species model for compressible reacting gas-liquid flows with phase change
School of Aeronautics, Northwestern Polytechnical University（西北工业大学航空学院）；National Key Laboratory of Aircraft Configuration Design（飞机设计国家重点实验室）；Institute of Extreme Mechanics, Northwestern Polytechnical University（西北工业大学极端力学研究所）
Ultra-low effective interfacial tension between miscible molecular fluids
本文利用在稠密背景流体中旋转的液滴的变形来研究可混溶分子流体之间的有效界面张力。我们发现，足够低的界面张力，旋转液滴开发哑铃形状，两个大的头部连接一个较薄的中心体。我们表明，这种形状不仅取决于密度和粘度之间的对比度的下降和背景流体，但也对流体的分子结构，因此在他们的界面上开发的应力，由于不同的分子相互作用。我们系统地研究了哑铃形的水-甘油混合物液滴在纯甘油容器中旋转的动力学。通过开发一个模型的变形的基础上的平衡的剪切应力反对的变形，施加的法向应力的下降和有效的界面张力，我们利用的时间演变的液滴形状来测量EIT。我们的研究结果表明，水-甘油系统中的EIT比以前的实验测量报告低几个数量级，并且与[Phys. Rev. X 6，041057，2016]中提出的相场模型计算的值非常一致。
