In the present work, the heat transfer characteristics around a single horizontal heated cylinders with different cross-sections (circular, square, rectangular, diamond and elliptical) in cross flow were studied experimentally. Experiments were carried out under uniform heat flux condition, with air as a working fluid. The tested cylinders had approximately the same total surface area of As ≈ 0.015 m2 and a length of 200 mm. The Reynolds number based on the upstream mean velocity and the equivalent hydraulic diameter, Dh, was ranged from 2200 to 22000. The results showed that, the average Nusselt number of the tested cylinders was increased with increasing Reynolds number. Highest Nusselt number was obtained for elliptic cylinder. Also, it was observed that the average Nusselt number of circular cylinder was the lowest value when compared with those for the other tested cylinders. Moreover, the present results were found to be in good agreement with the previously published experimental results.
Finally, empirical correlations for the average Nusselt number of the tested cylinders were obtained as a function of Reynolds number.