Local heat transfer from a single sphere to a turbulent air stream

Abstract

The local heat transfer between a sphere and a turbulent air stream was studied. The flow conditions covered Reynolds number between 2600 and 6100 and turbulence intensities from 0.45 to 6.0%. The results obtained show that the boundary layer over the leading surface becomes turbulent at the laminar separation point. This turbulent layer becomes reattached to the surface and separates further downstream, resulting in a turbulent wake. These phenomena occur at low Reynolds number through the interaction between the freestream turbulence and the boundary layer.