On a physically-realizable benchmark problem in internal natural convection

Abstract A new natural convection ‘benchmark problem’ for validating CFD codes is defined. In the subject problem, a cubical air-filled cavity, tilted at 0, 45°, or 90°, has one pair of opposing faces at different temperatures, Th and Tc, respectively, the remaining faces having a linear variation from Tc to Th. In contrast to some other benchmark problems, this problem is physically-realizable. Experimental techniques to establish the thermal boundary conditions and to measure the Nusselt number to 1% accuracy are reported. Measured Nusselt numbers at Rayleigh number equal to 4×104 are shown to agree with CFD predictions to within ±0.3%.