Heat Transfer in a Closed Domain of Inhomogeneous Supercritical Fluid under Weightlessness

Abstract

The process of heat transfer in a closed domain of temperature-density inhomogeneous supercritical fluid (SCF) heated or cooled from the boundaries under weightlessness is studied numerically. The calculations near the thermodynamic critical point are carried out with the use of 1D equations of Navier-Stokes, mass conservation, energy balance, and van der Waals equation of state. It is obtained that when the critical point approaches the characteristic time of “piston effect”, τPE, in inhomogeneous SCF significantly increases in comparison with the homogeneous case. The larger temperature-density inhomogeneity and the closer the critical point, the longer time of “piston effect”. In addition the heating of the fluid causes the temperature-density inhomogeneity to be stronger, whereas cooling leads to the weakening of the inhomogeneity.