Sequential solution strategies for the Cahn-Hilliard-Biot model
Erlend Storvik, Cedric Riethmüller, Jakub Wiktor Both, Florin Adrian Radu
TL;DR
The paper addresses the challenge of solving the coupled nonlinear CH-Biot equations that model flow in deformable porous media with phase changes. It compares two solution strategies: a monolithic Newton-based solver for the fully coupled system and a decoupled splitting scheme that iterates the CH, elasticity, and flow subsystems, both using a semi-implicit time discretization with a convex-concave split of the double-well potential. The study finds that the splitting approach offers superior robustness and often lower total CPU time, especially under stronger coupling governed by parameters such as surface tension $\gamma$ and swelling $\xi$, though it is not immune to convergence issues at high coupling. These findings inform practical choices for numerical solvers in poromechanics with phase-field dynamics and highlight directions for further stabilizing and refining splitting methods. The work advances numerical strategies for multi-physics phase-field poromechanics and supports more reliable simulations in engineering and materials science contexts.
Abstract
This paper presents a study of solution strategies for the Cahn-Hilliard-Biot equations, a complex mathematical model for understanding flow in deformable porous media with changing solid phases. Solving the Cahn-Hilliard-Biot system poses significant challenges due to its coupled, nonlinear and non-convex nature. We explore various solution algorithms, comparing monolithic and splitting strategies, focusing on both their computational efficiency and robustness.
