Experimental and numerical investigation on flow and heat transfer characteristics of a multi-waves internally spiral finned tube

摘要

In the present study, the flow and heat transfer characteristics of a multi-waves internally spiral finned tube was investigated by experiment and numerical simulation. Three-dimension computation was performed to predict the effect of inscribed circle diameter and spiral angle on the thermal performance in the finned tube. The numerical results agreed well with the experimental data. The maximum differences between the numerical results and the experimental data were approximately 5.2% for heat transfer coefficient and 4.1% for friction factor, respectively. The results showed that the heat transfer coefficient and friction factor of the finned tube were 7.94 - 8.67 and 5.39 - 5.84 times higher than those of the smooth tube, respectively. The (h/h_0)/(ΔP/ΔP_0)~(1/3) of the finned tubes ranged from 2.39 to 3.31. In this study, both heat transfer coefficient and friction factor decreased with the increase of inscribed circle diameter, while increased with the increase of spiral angle. In addition, the velocity and temperature fields were obtained to discern the mechanisms of heat transfer enhancement.