Heat transfer in the accelerated fully rough turbulent boundary layer.

Heat transfer behaviour of a fully rough turbulent boundary layer subjected to favorable pressure gradients was investigated experimentally using a porous test surface composed of densely packed spheres of uniform size. Stanton numbers and profiles of mean temperature, turbulent Prandtl number, and turbulent heat flux are reported. Three equilibrium acceleration cases (one with blowing) and one non-equilibrium acceleration case were studied. For each acceleration case of this study, Stanton number increased compared with zero pressure gradient values at the same position or enthalpy thickness. Turbulent Prandtl number was found to be approximately constant at 0.7-0.8 across the layer, and profiles of the nondimensional turbulent heat flux showed close agreement with those previously reported for both smooth and rough wall zero pressure gradient layers. (A)