Diffusion Stability of Mechanical Equilibrium in Compressible Isothermal Gases
— This paper is presented stability condition of mechanical equilibrium for diffusion of compressible isothermal gases in a cylindrical domain. Two general cases of the divergent stable motions were considered when density depended on the conditions 0  u div  and 0  u div . Stability criterion of mechanical equilibrium for the compressible gas mixture is proposed by defining continuous dependence of the velocity vector for the compressible flows in the Navier-Stokes problem from initial date. Using the parametrix method of theory nonlinear partial differential equations were obtained the velocity components for the transient compressible flows. Introduced stability condition for isothermal gases was predicted in the principal form by the energy conservation law and based on the transport equation for an appropriate convergent-divergent turbulent gas motion.
Diffusive and convective mixing of a propane-carbon dioxide binary mixture with pure nitrogen protoxide
The process of mixing propane-carbon dioxide binary mixtures with pure nitrogen protoxide is studied using a two-flask diffusion device. Experiments are carried out for different positions of starting gases in the flasks of the device depending on the pressure and concentration of mixing components. Mixing conditions and conditions under which molecular diffusion changes to concentration convection are found.
Stable diffusion boundaries in three-component gas mixtures
Within the framework of the Boussinesq approximation, as a function of the relationship between the partial diffusion factors, we have investigated an isothermal three-component gas mixture with respect to linear stability. In the stable diffusion region the process of isothermal mass transfer is described by standard Fick equations. We have determined the regions of increasing (diminishing) monotonie and oscillatory perturbations. We have investigated the relationship between the Rayleigh numbers and the parameters of the mixture.