Vanishing viscosity limit for the compressible Navier-Stokes equations with non-linear density dependent viscosities
Luca Bisconti, Matteo Caggio, Filippo Dell'Oro
TL;DR
The paper studies the vanishing viscosity limit for the 3D compressible Navier–Stokes equations with density-dependent viscosities in a bounded domain, including a drag term and no-slip boundary conditions. It develops two Kato-type boundary-layer criteria that guarantee convergence to a strong Euler solution as $\varepsilon\to0$ and $r_1(\varepsilon)\to0$, using a relative energy framework enhanced by a Kato-type fake boundary layer. The analysis extends prior work to general nonlinear viscosity laws by avoiding the augmented BDG approach and employing a direct relative-energy method, yielding convergence in density $\varrho\to\varrho^E$ in $L^\gamma$ and momentum $\varrho\mathbf{u}\to\varrho^E\mathbf{u}^E$ in $L^1$. The results provide explicit boundary-layer conditions and demonstrate how vanishing viscosity and drag parameters influence the inviscid limit, broadening applicability to nonlinear density-dependent viscosities and enriching the understanding of boundary-layer effects in compressible flows.
Abstract
In a three-dimensional bounded domain $Ω$ we consider the compressible Navier-Stokes equations for a barotropic fluid with general non-linear density dependent viscosities and no-slip boundary conditions. A nonlinear drag term is added to the momentum equation. We establish two conditional Kato-type criteria for the convergence of the weak solutions to such a system towards the strong solution of the compressible Euler system when the viscosity coefficient and the drag term parameter tend to zero.
