INHOMOGENEOUS INCOMPRESSIBLE VISCOUS FLOWS WITH SLOWLY VARYING INITIAL DATA

摘要

The purpose of this paper is to provide a large class of initial data which generates global smooth solution of the 3D inhomogeneous incompressible Navier-Stokes system in the whole space R-3. This class of data is based on functions which vary slowly in one direction. The idea is that 2D inhomogeneous Navier-Stokes system with large data is globally well-posed and we construct the 3D approximate solutions by the 2D solutions with a parameter. One of the key point of this study is the investigation of the time decay properties of the solutions to the 2D inhomogeneous Navier-Stokes system. We obtained the same optimal decay estimates as the solutions of 2D homogeneous Navier-Stokes system.