Multiple-relaxation-time lattice Boltzmann analysis of the flow and temperature structures in a ventilated cavity: impact of inlet fresh fluid jet

This paper presents a summary of a numerical study of mixed convection in a two-dimensional ventilated square cavity; it discusses the impact of the fresh inlet fluid jet on the flow and temperature structures. A saturated porous partition of thickness Ep = H/5 is positioned at the center of the cavity bottom with a height Hp between H/5 and H, while the vertical walls are kept adiabatic and impervious, the bottom horizontal wall is subject to a vertical thermal gradient. The momentum conservation equation uses the Darcy model with an energy equation, including the Brinkman extension, the multi-relaxation time collision factor based lattice Boltzmann method is used to solve the set of coupled equations. The numerical results present and discuss flow patterns and thermal field structures, reveal important physical quantities, such as the local and mean Nusselt value on the bottom wall. The parametric study presents the effects of Reynolds and Rayleigh numbers with respect to a given Darcy number and porous wall height. For a high Darcy number, the porous medium increases the surface of action of the cold fluid. In addition, by increasing the height of the porous wall, the thermal draft (Ra) has little influence on the Nusselt values.