Homogenization of parabolic problems with dynamical boundary conditions of reactive-diffusive type in perforated media
María Anguiano
TL;DR
This work develops a rigorous homogenization framework for parabolic reaction-diffusion problems in perforated domains with dynamical boundary conditions of reactive-diffusive type, incorporating the Laplace-Beltrami operator on the hole surfaces. Using energy methods, a Galerkin approach, and compactness arguments, the authors show that as the hole size ε→0 the solution converges to a nonlinear reaction-diffusion equation with an effective diffusion tensor Q that accounts for surface diffusion. The homogenized equation features volume- and boundary-penetration terms scaled by geometric factors |Y^*|/|Y| and |∂F|/|Y|, respectively, and the cell problems determine Q. This extends prior δ=0 results by incorporating boundary surface diffusion, providing a more complete macroscopic model for reactive-diffusive boundary effects in perforated media.
Abstract
This paper deals with the homogenization of the reaction-diffusion equations in a domain containing periodically distributed holes of size $\varepsilon$, with a dynamical boundary condition of reactive-diffusive type, i.e., we consider the following nonlinear boundary condition on the surface of the holes $$ \nabla u_\varepsilon \cdot ν+\varepsilon\,\displaystyle\frac{\partial u_\varepsilon}{\partial t}=\varepsilon\,δΔ_Γu_\varepsilon-\varepsilon\,g(u_\varepsilon), $$ where $Δ_Γ$ denotes the Laplace-Beltrami operator on the surface of the holes, $ν$ is the outward normal to the boundary, $δ>0$ plays the role of a surface diffusion coefficient and $g$ is the nonlinear term. We generalize our previous results established in the case of a dynamical boundary condition of pure-reactive type, i.e., with $δ=0$. We prove the convergence of the homogenization process to a nonlinear reaction-diffusion equation whose diffusion matrix takes into account the reactive-diffusive condition on the surface of the holes.