Abstract
The features of the change in the regimes "diffusion-gravitational concentration convection" in isothermal ternary gas mixtures have been studied experimentally and numerically. It is shown that, at a certain pressure, due to the difference in the diffusion coefficients of the components, an instability of mechanical equilibrium arises, leading to the appearance of structured convective formations. Calculation results are compared with experimental data on the location of the instability boundaries in the studied gas mixtures. Intensity of convective mixing is also influenced by the content of the component with the highest molecular weight in the initial mixture. In terms of Rayleigh numbers, a boundary relation is obtained that determines the regime change. The solution of the problem of multicomponent mixing in a cylindrical vertical channel of finite height with solid and impermeable boundaries for the substance made it possible to determine the concentration distribution along the length.