Abstract
The peculiarities of the change of the regimes “diffusion-gravitational concentration convection” have been studied numerically. It is shown that at a certain mixture composition and pressure, substantially nonlinear distributions of the concentrations of components arise at the expense of the difference in the diffusion coefficients of components, which lead to the corresponding distribution of the gaseous mixture density. This is a reason for the formation of structured formations and the rise of convective instability in the mixtures under study. The time of the rise of convective flows and of the mean velocity of the components transfer has been estimated. Obtained results are compared with experimental data.