An analytical wall-function for turbulent rough wall heat transfer

This paper reports the development of a refined wall-function strategy for the modelling of turbulent forced convection heat transfer over smooth and rough surfaces. In order to include the effects of fine-grain surface roughness, the present study extends a more fundamental work on the development of advanced wall functions of general applicability. The presently proposed model is validated through comparisons with data available for internal flows through channels and for external flows over flat and curved plates with both smooth and rough surfaces. The validation results suggest that the presently proposed form can be successfully applied to a wide range of heat transfer problems over smooth and fine-grain rough surfaces.