Numerical analysis of turbulent buoyant flows in enclosures: Influence of grid and boundary conditions

Turbulent natural convection in a differentially heated 2D cavity has been simulated numerically using the Shear Stress Transitional (SST) k–ω turbulence model. Comparisons with experimental benchmark values show that, in this case, conduction in the horizontal walls has a significant effect on the calculated results. They also show that the agreement between calculated and measured values at mid-height of the cavity does not suffice to establish the validity of the model and numerical procedure. Finally, these comparisons prove that grid independent results in good agreement with the experimental benchmark values can be obtained with a number of nodes smaller than that used for a Large Eddy Simulation (LES), as long as their distribution in the boundary layers is well chosen.