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.
Effect of diffusion channel inclination on stability of mechanical equilibrium in isothermal binary gas mixtures
Instability of mechanical equilibrium in isothermal binary gas mixtures is studied in experiments with different angles of inclination of the diffusion channel with respect to the vertical axis. As the angle of inclination is increased, the intensity of convective mass transfer is found to decrease and decay at a certain value of this angle. Experimental data are demonstrated to be consistent with estimates obtained from the linear stability theory.
Experimental Determination of the Boundary of Monotonic Disturbances upon Instability of the Mechanical Equilibrium in Three-Component Gas Mixtures
Instability of the mechanical equilibrium of ternary gas mixtures, in which the density from above is larger than from below, is investigated by the two-flask method under isothermal conditions at different pressures. A comparison of the experimental data with the results calculated within the framework of the linear analysis of stability has shown fair agreement in determination of the boundaries of instability.