Global weak solutions to a compressible Navier--Stokes/Cahn--Hilliard system with singular entropy of mixing

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Basarić, Danica, Giorgini, Andrea
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866916785675042816
author Basarić, Danica
Giorgini, Andrea
author_facet Basarić, Danica
Giorgini, Andrea
contents We study a Navier-Stokes/Cahn-Hilliard system modeling the evolution of a compressible binary mixture of viscous fluids undergoing phase separation. The novelty of this work is a free energy potential including the physically relevant Flory-Huggins (logarithmic) entropy, as opposed to previous studies in the literature, which only consider regular potentials with polynomial growth. Our main result establishes the existence of global-in-time weak solutions in three-dimensional bounded domains for arbitrarily large initial data. The core contribution is the derivation of new estimates for the chemical potential and the Flory-Huggins entropy arising from a density-dependent Cahn-Hilliard equation under minimal assumptions: non-negative $γ$-integrable density with $γ>\frac32$. In addition, we prove that the phase variable, which represents the difference of the mass concentrations, takes value within the physical interval $[-1,1]$ almost everywhere on the set where the density is positive.
format Preprint
id arxiv_https___arxiv_org_abs_2506_07835
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Global weak solutions to a compressible Navier--Stokes/Cahn--Hilliard system with singular entropy of mixing
Basarić, Danica
Giorgini, Andrea
Analysis of PDEs
We study a Navier-Stokes/Cahn-Hilliard system modeling the evolution of a compressible binary mixture of viscous fluids undergoing phase separation. The novelty of this work is a free energy potential including the physically relevant Flory-Huggins (logarithmic) entropy, as opposed to previous studies in the literature, which only consider regular potentials with polynomial growth. Our main result establishes the existence of global-in-time weak solutions in three-dimensional bounded domains for arbitrarily large initial data. The core contribution is the derivation of new estimates for the chemical potential and the Flory-Huggins entropy arising from a density-dependent Cahn-Hilliard equation under minimal assumptions: non-negative $γ$-integrable density with $γ>\frac32$. In addition, we prove that the phase variable, which represents the difference of the mass concentrations, takes value within the physical interval $[-1,1]$ almost everywhere on the set where the density is positive.
title Global weak solutions to a compressible Navier--Stokes/Cahn--Hilliard system with singular entropy of mixing
topic Analysis of PDEs
url https://arxiv.org/abs/2506.07835