COMPARISON OF THERMAL CHARACTERISTICS OF INCLINED FINNED TUBES AND TUBES WITH INCLINED FINS

The thermal efficiency comparison of tubes with inclined fins and inclined finned tubes is presented in this paper. The experimental results of heat transfer obtained on a finned pipe with fins inclined 45° respect the axial axis, are presented in this paper. The tested ratio between the fin diameter and the pipe diameter was D/d = 3. The experimental tests were carried out for different flow velocities (Re_d = 5000 to 30000) and different heat flow rates (Q = 100 to 720 W). Based on the experimental data, an empirical correlation, of the type Nu = C·Re_dⁿ, was developed. The results were compared with the ones obtained by other authors for an inclined, 40° degrees respect the direction of flux, using a conventional finned tube. It was found that the thermal efficiency of the tube with inclined fins was 75% higher.