文献类型：期刊文献

英文题名：Thermodynamically consistent modelling of two-phase flows with moving contact line and soluble surfactants

作者：Zhu, Guangpu[1];Kou, Jisheng[2,5];Yao, Bowen[3];Wu, Yu-shu[3];Yao, Jun[1];Sun, Shuyu[4]

机构：[1]China Univ Petr East China, Sch Petr Engn, Res Ctr Multiphase Flow Porous Media, Qingdao 266580, Shandong, Peoples R China;[2]Shaoxing Univ, Sch Civil Engn, Shaoxing 312000, Zhejiang, Peoples R China;[3]Colorado Sch Mines, Dept Petr Engn, 1600 Arapahoe St, Golden, CO 80401 USA;[4]King Abdullah Univ Sci & Technol, Div Phys Sci & Engn, Computat Transport Phenomena Lab, Thuwal 239556900, Saudi Arabia;[5]Hubei Engn Univ, Sch Math & Stat, Xiaogan 432000, Hubei, Peoples R China

年份：2019

卷号：879

起止页码：327

外文期刊名：JOURNAL OF FLUID MECHANICS

收录：SCI-EXPANDED(收录号：WOS:000487962900001)、、EI(收录号：20194007490511)、Scopus(收录号：2-s2.0-85072779494)、WOS

基金：G.Z. and J.K. contributed equally to this study. We are grateful to all reviewers for their constructive suggestions and comments. J.Y. and G.Z. acknowledge the support of the National Science and Technology Major Project (2016ZX05011-001), the Natural Science Foundation of China (51804325, 51674280 and 51774317) and Shandong Provincial Natural Science Foundation (ZR2019JQ21). The work of S.S. and J.K. is supported by the KAUST research fund awarded to the Computational Transport Phenomena Laboratory through grant BAS/1/1351-01-01.

语种：英文

外文关键词：contact lines; Navier-Stokes equations; multiphase flow

外文摘要：Droplet dynamics on a solid substrate is significantly influenced by surfactants. It remains a challenging task to model and simulate the moving contact line dynamics with soluble surfactants. In this work, we present a derivation of the phase-field moving contact line model with soluble surfactants through the first law of thermodynamics, associated thermodynamic relations and the Onsager variational principle. The derived thermodynamically consistent model consists of two Cahn-Hilliard type of equations governing the evolution of interface and surfactant concentration, the incompressible Navier-Stokes equations and the generalized Navier boundary condition for the moving contact line. With chemical potentials derived from the free energy functional, we analytically obtain certain equilibrium properties of surfactant adsorption, including equilibrium profiles for phase-field variables, the Langmuir isotherm and the equilibrium equation of state. A classical droplet spread case is used to numerically validate the moving contact line model and equilibrium properties of surfactant adsorption. The influence of surfactants on the contact line dynamics observed in our simulations is consistent with the results obtained using sharp interface models. Using the proposed model, we investigate the droplet dynamics with soluble surfactants on a chemically patterned surface. It is observed that droplets will form three typical flow states as a result of different surfactant bulk concentrations and defect strengths, specifically the coalescence mode, the non-coalescence mode and the detachment mode. In addition, a phase diagram for the three flow states is presented. Finally, we study the unbalanced Young stress acting on triple-phase contact points. The unbalanced Young stress could be a driving or resistance force, which is determined by the critical defect strength.