Abstract
An experimental study was carried out to investigate the unsteady heat transfer in the separated flow behind a circular cylinder in cross flow. The Reynolds number ranged from 1.2×10^3 to 4.8×10^4. Local and instantaneous heat flux on the surface was measured by a heat flux sensor and instantaneous temperature distribution on the surface was measured by an infrared camera. In the range of 3×10^3≤Re≤1×10^4, the Nusselt number in the separated flow region decreases suddenly with the decrease in the Reynolds number. The reason for this is explained that the effect of alternate reattaching flow on the rear face is intermittent below Re&sp;1×10^4, because the formation region of the rolling-up of the shear layer moves downstream.
