Natural convection boundary layer flow over horizontal and slightly inclined surfaces

Abstract

Laminar natural convection boundary-layer flow above horizontal and slightly inclined surfaces is considered. The effect of a small surface inclination on flow and transport is studied as a perturbation of flow over a horizontal surface. Solutions of the higher approximations have been numerically determined for the velocity, pressure and temperature fields for a Prandtl number of 0.7. These distributions are also given for the perfectly horizontal surface, for a wide range of Prandtl number. Both the surface conditions of uniform temperature and heat flux are considered. A Mach-Zehnder interferometer was used to study the nature of the laminar boundary-layer. The temperature distributions and heat transfer parameters were measured for the first time in such a flow, in air at atmospheric pressure. Present results may have a direct application to micro-meteorological and technological problems, and should clarify many aspects of natural convection flows which arise above horizontal and inclined planes through the initial impetus of unstably stratified fluid layers near the surface.