Abstract
The main objective of this article is to investigate the evolution of the mass transfer regimes in three-component gas mixture subject to the pressure and the diameter of diffusion channel. Two series of experiments on gaseous diffusion instabilities are reported. In one series the stability limits are investigated as a function of pressure and diameter for the system 0.4722 He + 0.5278 Ar - N2. In the other series the convection structures are made visible with the help of shadow method. The experimentalresults reveal that an increase in the pressure and the diameter of diffusion channel leads to a change of the type of mixing in ternary gas mixture.Numerical analysis of the mixing process is studied in a vertical cylindrical channel of a finite size and at the isothermal conditions. The governing equations are solved at the boundary conditions assuming the absence of matter through the walls of diffusion channel. Through the Rayleigh partial numbers, the influences of the pressure and the diameter of diffusion channel on the behaviour of diffusion and convective flows are examined. The present results are in good agreement with the experimental data.