Analysis of enhanced heat transfer characteristics in a bionic fish scale tube for turbulent flow

The miniaturization and compactness of heat exchangers are of great significance to marine power plant. Combining bionic technologies and passive technologies, a bionic fish scale tube (BFST) is proposed to enhance convective heat transfer coefficient of tube. The numerical simulation on flow and heat transfer characteristics of BFST is deliberated in turbulent flow region. Effects of various vertical heights, horizontal gaps, circumferential numbers and distance of adjacent fish scales have been investigated. Furthermore, the entropy generation and field synergy are also analyzed and correlations for Nusselt number and friction factor are obtained. These results suggest that local velocity increment, vortexes formed at the behind of fish scales and swirling of the flow are three main factors to improve the tube inner convective heat transfer coefficient. The Nusselt number is also significantly increased with the increment of vertical height, horizontal gap and circumferential numbers. Moreover, the maximum value of performance evaluation criteria at the ranges of studied can be up to 1.352 for BFST. S / S 0 of BFST are aggrandize with the Reynolds number increasing, which vary from 1.66 to 16.75. At last, the Nusselt number and friction factor correlations can predict the numerical data within R-square of 0.9910 and 0.9712 respectively.