Natural convection heat transfer from triangular finned cylinders

Natural convection heat transfer from aluminum cylinders with triangular fins was investigated for various fin numbers and fin dimensions. The fins were attached circumferentially to cylinder at a number of 18 for the frequent case, 12 for medium frequent case and 6 for the sparse case. The heights of the right triangular fins were 12cm, 6cm and 3cm while the other cathetus is congruent with the height of cylinder as 12cm. The tested heat sink is oriented at 7 different angular positions as the axis of the cylinder varies 45° from horizontal position. Constant heat flux is applied thorough the center of the cylinder and the inlet temperatures were measured with thermocouples. The results are given by Nu versus Ra curves. From the result of the experiments it is observed that fins increase the heat transfer considerably when compared to the straight cylinder. By increasing the frequency of the number of fins and the height of the triangular fin the heat transfer increases. The increment of the number of circumferential fins does not enhance the heat transfer as its magnitude. It is also observed that the heat transfer is enhanced at the vertical orientation angle (90° and 270°)