A micro-scale diffused interface model with Flory-Huggins logarithmic potential in a porous medium

Abstract: A diffused interface model describing the evolution of two conterminous incompressible fluids in a porous medium is discussed. The system consists of the Cahn-Hilliard equation with Flory-Huggins logarithmic potential, coupled via surface tension term with the evolutionary Stokes equation at the pore scale. An evolving diffused interface of finite thickness, depending on the scale parameter $\varepsilon$ separates the fluids. The model is studied in a bounded domain $\Omega$ with a sufficiently smooth boundary $\partial \Omega$ in $\mathbb{R}^d$ for $ d = 2 $, $3$. At first, we investigate the existence of the system at the micro-scale and derive the essential \textit{a-priori} estimates. Then, using the two-scale convergence approach and unfolding operator technique, we obtain the homogenized model for the microscopic one.