NATURAL CONVECTION TURBULENT BOUNDARY LAYERS NEXT TO HEATED VERTICAL SURFACES.

The turbulent natural convection boundary layer next to a heated vertical surface is analyzed by classical scaling arguments. It is shown that the fully developed turbulent boundary layer must be treated in two parts: an outer region constituting most of the boundary layer in which viscous and conduction terms are negligible and an inner region in which the mean convection terms are negligible. The inner layer can be identified as a constant heat flux layer. Linear regions of temperature and velocity are shown to exist next to the wall and are termed the conductive and thermo-viscous sublayers respectively. Finally, heat transfer and friction laws are proposed for the fully developed boundary layer.