Transient convective heat transfer in a helical coiled tube with pulsatile fully developed turbulent flow

Experiments were conducted to investigate the effects of population upon transient heat transfer characteristics for fully-developed turbulent flow in a uniformly heated helical coiled tube. The non-uniform feather of local heat transfer with steady flow was also examined. The secondary flow mechanism and the effect of interaction between the flow oscillation and secondary flow were analyzed on the basis of the experimental data. Some new phenomenon were observed and explained. A series of correlations were proposed for the average and local heat transfer coefficients both under steady and oscillatory flow conditions. The results showed that there were considerable variations in local and peripherally time-average Nusselt numbers for pulsating flow in a wide range of parameters.