Turbulent natural convection scaling in a vertical channel

Abstract

Using direct numerical simulation (DNS) data, this study appraises existing scaling laws in literature for turbulent natural convection of air in a differentially heated vertical channel. The present data is validated using past DNS studies, and covers a range of Rayleigh number, Ra between 5.4×105 and 2.0×107. We then appraise and compare the various scaling laws proposed by Versteegh and Nieuwstadt (1999), Hölling and Herwig (2005), Shiri and George (2008) and George and Capp (1979) with the profiles of the mean temperature defect, mean streamwise velocity, normal velocity fluctuations, temperature fluctuations and Reynolds shear stress. Based on the arguments of an inner (near-wall) and o..