Two-phase averaged system justification for ideal gases without conductivity
D Bresch, C Burtea, P Gonin--Joubert, F Lagoutière
TL;DR
The paper tackles the rigorous derivation of a two-phase averaged model for a one-dimensional compressible viscous fluid without heat conduction, addressing oscillations in density and temperature that persist in the limit. It develops a Hoff-type framework for a mesoscopic two-fluid system with a transported color function, then uses homogenization and Young measures to obtain a macroscopic two-phase model with two temperatures. A key contribution is establishing strong convergence of the stress tensor and deriving a kinetic equation for the associated Young measures, enabling a closed macroscopic description akin to Baer–Nunziato-type models. Numerical simulations illustrate the convergence between mesoscopic oscillatory solutions and the macroscopic two-phase system, confirming the theoretical results and highlighting Hoff-type discontinuities and their temporal decay.
Abstract
This article concerns the mathematical justification of an averaged system of partial differential equations governing the evolution of a two-phase mixture of compressible ideal fluids, with viscosity and without conductivity, in space dimension 1 with periodic boundary conditions. The derivation is done by some homogenization procedure. The originality and the difficulty of the paper consists in the fact that both the density and temperature are allowed to oscillate (because of the absence of heat conduction), so that the limiting model is a six-equations, two-pressures, two-temperatures model. The key point is to show the strong convergence of the stress tensor in $\(L^2((0,T)\times (0, 1))\)$. The main difficulties are to obtain uniform estimates in spite of the presence of oscillating coefficients in the energy equation. It requires to look at solutions with low regularity for the density and the temperature.
