Modeling of microconvection in a fluid between heat conducting solids

Unsteady convection in a fluid under weak gravity is modeled. Convection in a rectangular domain elongated in the direction of gravity and enclosed between two heat-conducting solids is investigated in the case of heat insulation of the ends of the rectangle and the periodic heat flow through the outer boundaries of the solids. In this case, the condition of zero total heat flux is satisfied. Convective fluid motions are described using two mathematical models: the classical Oberbeck–Boussinesq model and the microconvection model for an isothermally incompressible fluid. Results of the numerical studies confirm the quantitative and qualitative differences between the flow characteristics calculated using the two convection models. Fluid particle trajectories are presented. Effects due to various physical characteristics of the problem are studied.