FREE AND FORCED CONVECTION HEAT TRANSFER FROM SHORT INCLINED CIRCULAR CYLINDERS

Free and forced convective heat transfer rates from circular cylinders whose length to diameter ratio is small have been experimentally measured. The cylinders were arranged with their axes in a vertical plane and tests were conducted with the axes set at angles of between 0° and 90° to the horizontal. In the forced convective tests the cylinders were exposed to a horizontal air stream. The majority of the tests were undertaken with models having diameters of 19 mm and 25 mm with length to diameter ratios of between 1.5 and 16. The heat transfer rates were determined by the transient method i.e. by using solid aluminum models, heating them and measuring their temperature-time variation while they cooled. Significant differences between the present results and those observed in previous studies with models having large length to diameter ratio have been found. Methods of correlating both the free convective results and the forced convective results have been derived.