Navier-Stokes-Fourier system with general boundary conditions

Abstract: We consider the Navier--Stokes--Fourier system in a bounded domain $\Omega \subset R<sup>d$, $d=2,3$, with physically realistic in/out flow boundary conditions. We develop a new concept of weak solutions satisfying a general form of relative energy inequality. The weak solutions exist globally in time for any finite energy initial data and comply with the weak--strong uniqueness principle.