Experiment and numerical computations have been performed to compare the heat transfer and fluid flow characteristics of an internally finned tube with a smooth tube. The experimental set-up consists of a 1 m length aluminum tube having four numbers of longitudinal rectangular section fins attached inside periphery of the tube. The tube wall is subjected to a constant heat flux supplied from an electrical heater and the tube wall has been insulated from the surrounding atmosphere. High velocity air supplied into the tube by a blower and the flow rate was measured by means of an orifice meter where as the wall temperatures as well as inlet and outlet temperatures were measured by thermocouples. Numerical simulations have been carried out by solving three dimensional conservation equations of mass, momentum and energy with two equation based k-e turbulent model. It has been found from the experiment and CFD analysis that using a finned tube the heat transfer rate is increased compare to smooth tube but at the same time the friction factor also increases significantly. Nusselt number of finned tube was found to be considerably higher compared to smooth tube. The original contribution of the paper is the setting of a computational methodology for computing various heat transfer and fluid flow parameters while having the numerical confidence by comparing the CFD result with a small scale experimental measurement in the laboratory.

Nusselt number, finned tube, friction factor, smooth tube, heated surface, average temperature.