Characteristic features of heat transfer in inhomogeneous supercritical fluid

Abstract

“Speeding up” heating (so called “piston-effect”) of a closed domain of supercritical fluid is studied using 1D Navier-Stokes equations and van der Waals equation of state. Time dependences of temperature, density, pressure and velocity distributions are calculated for various initial conditions on temperature, density and gravity. It is shown that for some threshold value ε of the distance from critical point density stratification caused by gravity does not affect the characteristic time of the piston-effect τPE. The time τPE rises more rapid as a function of characteristic density μ when fluid has the step temperature-density stratification in comparison with that for the homogeneous density. The results are compared with the analytical solutions obtained by Onuki.