Nonlinear stability of a composite wave to the Cauchy problem of 1-D full compressible Navier-Stokes-Allen-Cahn system

TL;DR

This paper proves the nonlinear stability and convergence of solutions to a one-dimensional compressible Navier-Stokes-Allen-Cahn system towards a composite wave, using energy methods and considering large initial perturbations.

Contribution

It establishes the global existence and asymptotic stability of solutions near a composite wave for the full system with large initial perturbations, especially when the adiabatic exponent is close to 1.

Findings

Existence of a unique global strong solution converging to the composite wave.

Stability holds even with large initial perturbations and wave strength.

Convergence is proven using an elementary energy method.

Abstract

The compressible Navier-Stokes-Allen-Cahn system models the motion of a mixture of two macroscopically immiscible viscous compressible fluids. In this paper, we are concerned with the large time behavior of solutions to the Cauchy problem of the one-dimensional full compressible Navier-Stokes-Allen-Cahn system. If the Riemann problem of the corresponding Euler system admits a solution which is a linear combination of 1-rarefaction wave and 3-rarefaction wave, we proved that a global strong solution to the compressible Navier-Stokes-Allen-Cahn system exists uniquely and converges to the above composite wave as time goes to infinity, provided that the adiabatic exponent $\gamma$ is closed to $1$. Here the initial perturbations except for the temperature function of the fluid, and the strength of rarefaction waves can be arbitrarily large. The proof is given by an elementary energy method that takes into account the effect of the phase field variable $\chi(t,x)$ and the complexity of nonlinear waves.