Heat transfer enhancement of a copper tube with constant wall temperature using a novel horizontal perforated teardrop-shaped turbulators (PTST)

Considering that turbulators generally have a high pressure drop level and as a result low thermal performance, in this research a numerical study conducted for a new form of aerodynamically designed turbulators that are concentrically perforated to have less pressure drop. In this study, the effects of a novel perforated teardrop-shaped turbulator (PTST) on the hydro-thermal parameters were numerically examined. Results were compared with a plain tube and a tube equipped with a simple teardrop-shaped turbulator (STST). PTST with the horizontal perforation geometry including a square, hexagon, octagon, and circle holes was installed inside a copper tube with constant wall temperature. The effect of the horizontal perforation cross-section area on the heat transfer and pressure drop was also evaluated. Tests were conducted under turbulence flow rates in the range of 0.044-0.099 kg/s. To select the optimal case, the thermal enhancement factor (TEF) was calculated. The results clarified that the hole area and hole geometry have a significant effect on TEF and hydro-thermal pa-rameters. The highest heat transfers and pressure drop took place in the presence of the STST, while the highest TEF was equivalent to 1.39 and occurred in the presence of a PTST with a 5 mm diameter circular hole. The heat transfers in the presents of STST and PTST increased by 310.1% and 298% compared to the plain tube. Finally, a correlation expressing the relationship of TEF and perforation area was also presented based on curve fitting.