Heat Transfer around a Circular Cylinder in Separated Air Flow.

Abstract

An experimental study has been conducted to determine the heat transfer characteristics around a circular cylinder attached to the separated flow of air shed from a fence. The fence was located vertically to the flow with a height of H=40mm. d/H was constant at 0.638, where d is the cylinder diameter of 25.5mm. X/H were 0.50, 0.775, and Y/H ranged from 0.525 to 1.50, where X and Y are, respectively, the distances between the axis of the cylinder and the front face of the fence, and the bottom wall of the test section. The Reynolds number Re based on the cylinder diameter and the velocity of the undisturbed flow ranged from 1.9×104 to 6.0×104. It was found that the maximum local Nusselt number changes drastically in the vicinity of Y/H=1.0∼1.11, and that the maximum mean Nusselt number occurs in the neighborhood of Y/H=1.24∼1.43 for X/H=0.50, and 1.3∼1.4 for X/H=0.775.