INSTABILITY OF MECHANICAL EQUILIBRIUM AND SOME FEATURES OF CONCENTRATION CONVECTION IN ISOTHERMAL TERNARY GASEOUS SYSTEMS

Abstract

Experimental study of the occurrence of convective flows in a three-component gas mixture He + R12 – Ar at various pressures and concentrations of the miscible components has been carried out. It is shown that the intensity of convective flows increases with increasing pressure. It is noted that in the system under consideration, the occurrence of convective flows is possible when the content of Freon-12 in the mixture is more than 0.1 mole fraction. A numerical study of the instability of mechanical equilibrium in the system He + R12 – Ar with significantly different diffusion coefficients of gas mixture components has been carried out by means of the splitting scheme in terms of physical parameters. The presented mathematical model makes it possible to describe the process of formation of a convective structure for various compositions of mixture. The onset of instability is accompanied by the appearance of nonlinear isoconcentration lines. Within the numerical framework, the onset times of various mixing regimes are determined.