Introduction to the generalized theory of non-equilibrium Cahn-Hilliard phase transitions

E. A. Lukashev ; E. V. Radkevich ; N. N. Yakovlev ; O. A. Vasil'eva

Journal of Samara State Technical University, Ser. Physical and Mathematical Sciences, Tome 21 (2017) no. 3, pp. 437-472

Résumé

The occurrence of convective currents and their development from regular forms with the subsequent transition to irregular turbulent currents draw attention to the fact that they are responsible for the efficiency of many technological processes of heat and mass transfer. Such technological processes are basic in the chemical, petrochemical, power, metallurgical and other industries. Convective flows arise in liquids and gases in the gravitational field in the presence of spatial inhomogeneity of the density created by the inhomogeneity of the temperature and the concentration of components arising during, for example, chemical reactions or other causes. With increasing temperature difference, the resting liquid loses its stability, which then leads to the appearance of a convective flow (Rayleigh–Bénard instability). A further increase in the temperature difference leads to an instability of the primary convective flow, and the hydrodynamic crisis leads to a heat transfer crisis. The paper reconstructs the early stage of the Rayleigh–Bénard convective instability considered as a nonequilibrium phase transition with the spinodal decomposition (diffusion separation) mechanism.

Détail

Keywords: critical processes, Rayleigh–Bénard instability, nonequilibrium phase transition, Ginzburg–Landau potential, pumping of internal energy, free Gibbs energy, models of continuum mechanics.
Mots-clés : diffusion separation