Global well-posedness of strong solutions to a bulk-surface Navier-Stokes-Cahn-Hilliard model with non-degenerate mobilities in two dimensions
Jonas Stange
TL;DR
The paper proves the global well-posedness of strong solutions for a two-dimensional bulk–surface Navier–Stokes–Cahn–Hilliard model with non-degenerate mobilities and dynamic bulk–surface coupling. It develops new regularity theory for convective bulk–surface Cahn–Hilliard equations and a bulk–surface Stokes system with variable coefficients, then constructs global strong solutions via a semi-Galerkin approach combined with Schauder fixed-point arguments and rigorous a priori estimates. Uniqueness and continuous dependence on initial data are shown for $L\in(0,\infty]$, while the case $L=0$ is excluded except in a special compatible setting when $K=L=0$. The results advance the mathematical understanding of coupled bulk-surface diffuse-interface dynamics and provide a rigorous foundation for models of membrane-fluid interactions with mass exchange.
Abstract
We examine a thermodynamically consistent diffuse interface model for bulk-surface viscous fluid mixtures. This model consists of a Navier--Stokes--Cahn--Hilliard model in the bulk coupled to a surface Navier--Stokes--Cahn--Hilliard system on the boundary. In this paper, we address the global well-posedness of strong solutions in the two-dimensional setting, also covering the physically meaningful case of non-degenerate mobility functions. Lastly, we prove the uniqueness of the corresponding strong solutions and their continuous dependence on the initial data. Our approach hinges upon new well-posedness and regularity theory for a convective bulk-surface Cahn--Hilliard equation with non-degenerate mobilities, as well as a bulk-surface Stokes equation with non-constant coefficients.
