期刊名称:Journal of Computational Science and Technology
电子版ISSN:1881-6894
出版年度:2008
卷号:2
期号:2
页码:318-329
DOI:10.1299/jcst.2.318
出版社:The Japan Society of Mechanical Engineers
摘要:A numerical method for solving Navier-Stokes equations and combined with a phase-field interface model is applied to flow problems of motion of an incompressible isothermal two-phase fluid with a high density ratio on a solid surface. Based on the free-energy theory, a fluid interface is described as a finite volumetric zone across which the physical properties vary continuously. The wettability of a solid surface is taken into account through a simple boundary condition derived from the increase in free energy on the surface. The phase-field approach simplifies the capture of motions of a fluid interface on a surface (contact line). The major findings from the simulations are as follows: (1) the contact-line motions of the liquid column under gravity are well predicted in comparison with the available data; (2) the static contact angle is flexibly controlled by a parameter of the wetting potential of the surface; (3) the capillary force is evaluated appropriately; (4) the acceleration of the two-phase flow in a channel with a local hydrophilic surface is predicted and observed to be in qualitative agreement with the experimental data; and (5) the displacement and breakup of a single drop on a flat solid wall are well predicted qualitatively. These results prove that the phase-field method can be employed for simulating air-water flows on a surface with heterogeneous wettability.
关键词:Computational Fluid Dynamics;Diffuse-Interface Model;Interface Tracking;Wettability;Contact Line