COMPARISON EXERCISE FOR COMPUTATIONS OF TURBULENT NATURAL-CONVECTION IN ENCLOSURES

A comparison is made between the numerical results obtained by 10 groups for a standard test case, which was defined for turbulent natural-convection flow in enclosures. The standard case considers air at a Rayleigh number of 5 X 10(10) in a square, differentially heated enclosure with adiabatic horizontal wads. The turbulence is modeled by a standard k-epsilon model. Some contributions find a strong grid dependence of the transition point in the vertical boundary layers, which prevents finding the grid-independent solution. In some contributions the boundary condition for epsilon on the wall leads to convergence problems. The solution that shows the best agreement with half of the contributions is taken as the numerical reference solution.