Forced Convection Heat Transfer From on Elliptic Cylinder of Axis Ratio 1 : 2

Abstract

An experimental investigation has been made to clarify the heat transfer characteristics of an elliptic cylinder of axis ratio 1 : 2. The testing fluid was air and the Reynolds number ranged from about 5000 to 90000. The angle of attack α was varied from 0°to 90°. The local heat transfer behavior is clarified and it is quite different from that of a circular cylinder. In the region of α>40°, the heat transfer rate from the upstream surface, on which a laminar boundary layer develops, becomes lower than that from the downstream surface in the separated flow region. The mean heat transfer coefficient Nu_m depends upon the angle of attack along with the Reynolds number. It is found that Nu_m is the highest for α=75° to 90° and is the lowest for α=30° over the whole Reynolds number range studied. The mean heat transfer rate from the elliptic cylinder investigated in the present work is higher than that from the circular cylinder at all the angles of attack over the Reynolds number range studied.