Convective heat transfer and pressure drop of a tube with internal longitudinal fins

The fluid flows and heat transfer characteristics of a tube with internal longitudinal fins were investigated experimentally and numerically. The realizable turbulence model was adopted to simulate the problem, whose results indicate a good agreement with the measured data. Compared with the circular annulus tube, it was shown that the internal longitudinal finned tube provides excellent heat transfer performance greater than those of the circular annulus tube, with a great increase of simultaneous pressure drops. Furthermore, there exists a critical Reynolds number, about 1500, when the Reynolds number is less than the critical value, and the Nusselt number of an internal longitudinal finned tube will be smaller than that of a circular annulus tube in laminar flow. On the other hand, the transition Reynolds number for a tube with internal longitudinal fins from laminar to turbulent is greatly decreased due to the existence of internal longitudinal fins.