Abstract
Spatio-temporal characteristic of heat transfer accompanied by the flow separation and reattachment was investigated by using a high-speed infrared thermograph that recorded the temperature fluctuation on a heated thin-foil. In this study, the heat transfer behind a backward-facing step, a forward-facing step, and a blunt plate were investigated. In each configuration, the heat transfer in the flow reattaching region had spot-like characteristics, which spread with time and overlapped with others to form a complex feature in terms of spatio-temporal characteristics of the heat transfer. The mean Nusselt number distribution behind the reattaching region was approximately proportional to 2/3 power of Reynolds number, as indicated in the previous researches. The instantaneous heat transfer distribution had a spanwise periodicity in the flow reattaching region, the wavelength of which seems strongly dependent on the step height.
