FORCED CONVECTION HEAT TRANSFER FROM AN ELLIPTIC CYLINDER OF AXIS RATIO 1:2.

Abstract

An experimental investigation was 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 90,000. The angle of attack alpha was varied from 0 degree to 90 degree . . The local heat transfer behavior is clarified and it is quite different from that of a circular cylinder. In the region of alpha greater than 40 degree , 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 alpha equals 75 degree to 90 degree and is the lowest for alpha equals 30 degree 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.