Uniform regularity and vanishing viscosity limit for the free surface   Navier-Stokes equations
  We study the inviscid limit of the free boundary Navier-Stokes equations. We prove the existence of solutions on a uniform time interval by using a suitable functional framework based on Sobolev conormal spaces.   This allows us to use a strong compactness argument to justify the inviscid limit. Our approach does not rely on the justification of asymptotic expansions. In particular, we get a new existence result for the Euler equations with free surface from the one for Navier-Stokes. 
Nader Masmoudi and Fr\'ed\'eric Rousset
math.AP