arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2104.02626physics.flu-dyncs.NAmath.NAphysics.comp-ph
收藏

含可溶性表面活性剂运动接触线的热力学自洽模型及其守恒数值逼近

A Thermodynamically Consistent Model and Its Conservative Numerical Approximation for Moving Contact Lines with Soluble Surfactants

Quan Zhao, Weiqing Ren, Zhen Zhang

摘要:

我们推导出一个连续的尖锐的界面模型与可溶性表面活性剂的移动接触线在一个连续一致的框架。该模型包括等温两相不可压缩纳维-斯托克斯方程的流体动力学和体\slash表面对流扩散方程的表面活性剂的传输。基于总自由能量耗散原理,推导了界面条件、滑移边界条件、动态接触角条件和吸附\slash脱附条件。特别是,我们恢复经典的吸附等温线从不同形式的表面自由能。然后在两个空间维度上对模型进行数值求解。我们提出了一个欧拉弱形式的纳维-斯托克斯方程与任意拉格朗日欧拉弱形式的表面活性剂输运方程。提出了有限元近似离散的两个弱的提法上的移动网格。所得到的数值方法被证明是保存的表面活性剂的总质量。通过使用所提出的模型及其数值方法,我们调查液滴的扩散和迁移在表面活性剂的存在下,并研究其依赖于各种无量纲吸附参数。

英文摘要:

We derive a continuum sharp-interface model for moving contact lines with soluble surfactants in a thermodynamically consistent framework. The model consists of the isothermal two-phase incompressible Navier-Stokes equations for the fluid dynamic and the bulk\slash surface convection-diffusion equations for the surfactant transportation. The interface condition, the slip boundary condition, the dynamic contact angle condition, and the adsorption\slash desorption condition are derived based on the principle of the total free energy dissipation. In particular, we recover classical adsorption isotherms from different forms of the surface free energy. The model is then numerically solved in two spatial dimensions. We present an Eulerian weak formulation for the Navier-Stokes equations together with an arbitrary Lagrangian-Eulerian weak formulation for the surfactant transport equations. Finite element approximations are proposed to discretize the two weak formulations on the moving mesh. The resulting numerical method is shown to conserve the total mass of the surfactants exactly. By using the proposed model and its numerical method, we investigate the droplet spreading and migration in the presence of surfactants and study their dependencies on various dimensionless adsorption parameters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑