Abstract
An experimental study was performed on the heat transfer in the separated flow behind a circular cylinder for Reynolds numbers from 100 to 30000. In this paper, unsteady and three-dimensional characteristics are described. Instantaneous temperature distribution and its fluctuating pattern on the cylinder surface were measured by an infrared camera. It was found that the pair of streamwise vortices formed in the near wake enhances the heat transfer around the rear stagnation of the cylinder. In particular, the streamwise vortices of 'mode A', which is formed around Re=200,effectively enhances the heat transfer around the rear stagnation. For 300<Re ≤ 15000,the heat transfer around the rear stagnation increases remarkably with the increase in the Reynolds number. This is caused by the inception of the alternative reattaching flow on the rear face of the cylinder, interlocked by the vortex shedding behind the cylinder.
