Simulation of convection in a two-phase system under conditions of diffusive evaporation in a closed region

The problem of thermocapillary convection in a flat bounded region filled with liquid and gas in contact along the interfacial interface is studied under weak evaporation. To study the processes of heat and mass transfer and the parameters of phase transitions under conditions of local heating, a two-sided mathematical model based on the Oberbeck–Boussinesq equations is proposed. The characteristics of mass transfer through the thermocapillary interface due to evaporation and vapor content in the gas layer are analyzed taking into account the influence of the Soret and Dufour effects. The results of a numerical study of the evolution of the interface and unsteady flows in a cell are presented. The calculation of the main characteristics of the liquid-gas system and the position of the interface at each moment of time was carried out using a specially developed numerical algorithm. The presented model makes it possible to describe the formation of characteristic thermal and concentration structures and transient modes of cellular convection with a complex configuration of flows in layers.