Buoyancy-Induced Convection in a Partially Porous Chamber Filled with a Fluid of Variable Viscosity Under Periodically Heated Source

This study deals with the thermal gravitational convection of a variable viscosity fluid in a closed two-dimensional cavity in the presence of a porous layer. In addition, at the lower edge of the region there is a heat-conducting energy source with periodic heat release. The problem has been solved in dimensionless non-primitive parameters including stream function and vorticity using the finite difference schemes on a uniform structured mesh. The influence of the defining characteristics of heat transfer such as the Darcy and Rayleigh numbers, the height of the porous layer, the heater location, as well as the frequency of the heat dissipation from the heater, has been studied. The results have been demonstrated using isolines of the stream function and temperature combined with time dependences of the integral characteristics of heat transport for various values of dimensionless parameters. The conclusions obtained have demonstrated that the periodic nature of heat dissipation completely determines the periodicity of convective processes in the cavity. In addition, the presence of a porous layer and the ability to change the position of the heater make it possible to control heat removal.