Numerical Investigation on Heat Transfer and Fluid Flow in a Circular Tube with Rectangular Cut Perforated Twisted Tape

Maximizing heat transfer augmentation is pivotal for optimizing energy efficiency, boosting performance, and advancing various industrial processes across a spectrum of applications. Passive heat transfer enhancement improves efficiency through surface modifications or designs, requiring no extra energy input. Passive heat transfer enhancement techniques encompass surface roughening, extended surfaces (such as fins), vortex generators, and patterns like ribs or dimples to augment heat exchange naturally without additional energy input. A numerical investigation is performed on a circular pipe with rectangular cut-circular perforated twisted tape (RCPTT) to investigate its thermo-hydraulic performance in a turbulent flow. Nusselt number (Nu), friction factor (f), and Thermal performance Factor (TPF) are calculated for the circular pipe with RCPTT and compared with Rectangular cut Twisted Tape (RCTT), Perforated Twisted tape (PTT), and classic twisted tape (TT) for Reynolds number (Re) spanning 10,000 to 19,000. A Uniform heat flux of 25,000 W/m2 is considered for the present study. A CFD Software program, ANSYS FLUENT 18.2, runs numerical simulations. RCPTT has a larger heat transfer and a higher pressure drop than classic twisted tape. In the RCPTT, the Nusselt number is 5% higher, and the friction factor is 5% higher than in a standard twisted tape. The highest TPF is 1.92 at a Reynolds number of 19,000.