Double Diffusion in $Ar-N_2$ Binary Gas System at the Constant Value of Temperature Gradient

An experimental study of the "diffusion-gravitational convection" transition boundary in an $Ar-N_2$ binary system at different pressures and a constant temperature gradient is performed. It is shown that the diffusion is replaced by the gravitational convection at a pressure p ≈ 0.5 MPa. In terms of the stability theory, a perturbation boundary line is determined, dividing the Rayleigh numbers plane into the regions of the diffusion and the convective mass transfer. The experimental data agree well with the theoretical values.