English

Phase-field modeling of isothermal quasi-incompressible multicomponent liquids

Soft Condensed Matter 2016-09-28 v2 Fluid Dynamics

Abstract

In this paper general dynamic equations describing the time evolution of isothermal quasi-incompressible multicomponent liquids are derived in the framework of the classical Ginzburg-Landau theory of first order phase transformations. Based on the fundamental {equations of continuum mechanics}, a general convection-diffusion dynamics is set up first for compressible liquids. The constitutive relations for the diffusion fluxes and the capillary stress are determined in the framework of gradient theories. {Next the general definition of incompressibility is given}, which is taken into account {in the derivation} by using the Lagrange multiplier method. To validate the theory, the dynamic equations are solved numerically for the quaternary quasi-incompressible Cahn-Hilliard system. It is demonstrated that variable density (i) has no effect on equilibrium (in case of a suitably constructed free energy functional), {and (ii) can} influence non-equilibrium pattern formation significantly.

Keywords

Cite

@article{arxiv.1608.02218,
  title  = {Phase-field modeling of isothermal quasi-incompressible multicomponent liquids},
  author = {Gyula I. Toth},
  journal= {arXiv preprint arXiv:1608.02218},
  year   = {2016}
}