Special Session 89: Recent trends in mathematical fluid mechanics

Two-phase compressible/incompressible Navier--Stokes system with inflow-outflow boundary conditions

Milan Pokorny
Charles University
Czech Rep
Co-Author(s):    Aneta Wr\`oblewska-Kami\`nska (Warsaw), Ewelina Zatorska (London)
Abstract:
We prove the existence of a weak solution to the compressible Navier--Stokes system with singular pressure that explodes when density achieves its congestion level. This is a quantity whose initial value evolves according to the transport equation. We then prove that the ``stiff pressure limit gives rise to the two-phase compressible/incompressible system with congestion constraint describing the free interface. We prescribe the velocity at the boundary and the value of density at the inflow part of the boundary of a general bounded $C^2$ domain. For the positive velocity flux, there are no restrictions on the size of the boundary conditions, while for the zero flux, a certain smallness is required for the last limit passage.