Homogenization of a multiscale multi-continuum system

TL;DR

This paper investigates the homogenization of a multiscale dual-continuum system with a focus on the case where interaction terms scale as O(1/ε), revealing complex features like convection and negative coefficients in the homogenized model.

Contribution

It provides the first rigorous analysis of homogenization for dual-continuum systems with O(1/ε) interaction scaling, including convergence proof and rate derivation.

Findings

Homogenized system contains convection terms.

Homogenized interaction coefficients can be negative.

Established convergence and convergence rate.

Abstract

We study homogenization of a locally periodic two-scale dual-continuum system where each continuum interacts with the other. Equations for each continuum are written separately with interaction terms (exchange terms) added. The homogenization limit depends strongly on the scale of this continuum interaction term with respect to the microscopic scale. In J. S. R. Park and V. H. Hoang, {\it Hierarchical multiscale finite element method for multicontinuum media}, arXiv:1906.04635, we study in details the case where the interaction terms are scaled as $O(1/\ep^2)$ where $\ep$ is the microscale of the problem. We establish rigorously homogenization limit for this case where we show that in the homogenization limit, the dual-continuum structure disappears. In this paper, we consider the case where this term is scaled as $O(1/\ep)$. This case is far more interesting and difficult as the homogenized problem is a dual-continuum system which contains features that are not in the original two scale problem. In particular, the homogenized dual-continuum system contains extra convection terms and negative interaction coefficients while the interaction coefficient between the continua in the original two scale system obtains both positive and negative values. We prove rigorously the homogenization convergence. We also derive rigorously a homogenization convergence rate. Homogenization of dual-continuum system of this type has not been considered before.