Dissipative Solutions to a Compressible Non-Newtonian Korteweg System with Density-Dependent Viscous Stress Tensor
Didier Bresch, Christophe Lacave, Maja Szlenk
TL;DR
The paper addresses the existence of dissipative solutions for a compressible, non-Newtonian Navier–Stokes–Korteweg system with density-dependent viscosity and capillarity in a periodic setting. It employs a relative entropy framework to quantify the distance to a smooth reference state and derives a dissipative inequality that yields weak-strong uniqueness. The main contribution is extending the dissipative-solution theory from Newtonian to non-Newtonian viscosities under specified growth and monotonicity conditions, using a Galerkin-based approximation and monotonicity methods to pass to the limit. This advances the understanding of well-posedness for compressible non-Newtonian fluids with capillarity and provides a robust tool for analyzing stability against smooth solutions in applied settings.
Abstract
The main objective of this paper is to prove that if capillarity effect is taken into account then there exist dissipative solutions to a system describing viscoplastic compressible flows with density dependent viscosities in a periodic domain $\T^d$ with $d=2,3$. We calculate the relative entropy inequality and in consequence show existence of dissipative solutions and the weak-strong uniqueness for this system. Our result extends the recent result concerning the link between Euler--Korteweg and Navier--Stokes--Korteweg systems for Newtonian flows (when the viscosity depends on the density) [See D.~Bresch, M. Gisclon, I. Lacroix-Violet, {\it Arch. Rational Mech. Anal.} (2019)] to non-Newtonian flows.
