On the non-homogeneous Navier-Stokes system with Navier friction   boundary conditions
  We address the issue of existence of weak solutions for the non-homogeneous Navier-Stokes system with Navier friction boundary conditions allowing the presence of vacuum zones and assuming rough conditions on the data. We also study the convergence, as the viscosity goes to zero, of weak solutions for the non-homogeneous Navier-Stokes system with Navier friction boundary conditions to the strong solution of the Euler equations with variable density, provided that the initial data converge in $L^{2}$ to a smooth enough limit. 
Lucas C. F. Ferreira, Gabriela Planas and Elder J. Villamizar-Roa
math.AP