Experimental study on convective heat transfer and pressure drop of two different internally finned tubes

The influence of forming ridge on heat transfer and pressure drop characteristic of internally longitudinal finned tubes which have the similar geometric size and shape were investigated experimentally. The correlations of friction factor and Nusselt number vs Reynolds number in the experimental range were obtained. It can be found that the ridge has the ability of enhancing heat transfer, however, the pressure drop will be increased simultaneously. By comparing the comprehensive performance of the tested tubes, it can be found that the internally finned tube with ridged-fin meets the requirements of inter-cooler of compressor better.