Stability of composite Wave of Planar Viscous Shock and Rarefaction for 3D Barotropic Navier-Stokes Equations
Jiajin Shi, Yi Wang
TL;DR
This work establishes nonlinear time-asymptotic stability of a composite wave formed by a planar rarefaction and a planar viscous shock for the three-dimensional compressible barotropic Navier–Stokes equations under generic $H^2$ perturbations without zero-mass restrictions. The authors develop an $a$-contraction framework with time-dependent shifts and a weighted energy functional, augmented by an effective velocity to exploit viscous dissipation in Eulerian coordinates. Under small composite-wave strength, they prove global existence of a strong solution and convergence to the composite wave up to a sublinear shift, with precise control of wave interactions and decay in the transverse directions. This advances multidimensional stability results for composite wave patterns in viscous compressible flows and extends the $a$-contraction approach to the 3D barotropic NS system with physical viscosities in a periodic transverse setting.
Abstract
We prove the nonlinear time-asymptotic stability of the composite wave consisting of a planar rarefaction wave and a planar viscous shock for the three-dimensional (3D) compressible barotropic Navier-Stokes equations under generic perturbations, in particular, without zero-mass conditions. It is shown that if the composite wave strength and the initial perturbations are suitably small, then 3D Navier-Stokes system admits a unique global-in-time strong solution which time-asymptotically converges to the corresponding composite wave up to a time-dependent shift for planar viscous shock. Our proof is based on the $a$-contraction method with time-dependent shift and suitable weight function.
