Study of Diffusion Instability in Ternary Gas Mixtures under Nonisothermal Conditions

The main objective of this article is to investigate the effect of heating (from below or above) on stability of mechanical equilibrium in binary and ternary gas mixtures. Three series of experiments on instabilities in are reported gaseous diffusion. In one series occurrence of convective flows under diffusive mixing are investigated in the systems N2O – CO2 and CO2 – N2O heated from below. The temperature difference when the transition between the diffusion and the convective processes happen is higher at the bottom arrangement of N2O. In the second series the influence of temperature difference are studied in the mixture 0.279 C3H8 + 0.721CO2 – CO2. The rate of convective mass transfer increases sufficiently. In the third series the convective mass transfer is examined in the system 0.4736 He + 0.5264 Ar – N2 heated from above. The experimental results reveal that the intensity of unstable process decreases until 420.0 K reaching a minimum value. Linear stability theory is applied to determine the boundary of transition from the state of diffusion to the region of convection. The results of numerical study are in good agreement with the experiments