Influence of rotating twisted tape turbulator and nanofluids on heat transfer characteristics in a tube.

In this study, the heat transfer characteristics of water and three different water based nano fluids comprising of copper oxide (CuO), zinc oxide (ZnO) and titanium dioxide (TiO2) with constant 0.2% volume concentration (φ) of respective nanoparticles in a bare tube and bare tube fitted with “rotating twisted tape turbulator (RTTT)” of twist ratio (y = 2.88) inside, was examined. The flow rate of the working fluids (1–6 LPM) and the rotational speed of the twisted tape turbulator (TTT) (0-300 RPM) were considered as variable constraints and their influence on heat transfer characteristics were evaluated. It was detected that for all the working fluids, the convective heat transfer coefficient intensifies with upsurge in the flow rate and rotational speed of the TTT. A constant wall heat flux condition was used in the contemporary investigation. The literature review reveals that most of the research work focuses on the study of heat transfer characteristics in a bare tube with TTT. Minimal research work has been carried out on the usage of ‘rotating twisted tape turbulators’ using nano fluids as working fluid to augment the heat transfer characteristics. Further, the results indicate that the heat transfer characteristics may be enhanced by rotating the twisted tape turbulator at 300 RPM in a plain tube and by maintaining the flow rate of the working fluids at 6 LPM. [ABSTRACT FROM AUTHOR]