Journal of Thermal Analysis and Calorimetry, cilt.148, sa.15, ss.7811-7828, 2023 (SCI-Expanded)
In this study, the effects on thermal performance and entropy production of new type turbulators with different blade angles and numbers, which are placed in a circular shaped pipe and manufactured in a 3D printer, were investigated experimentally. According to the experiments performed in the Reynolds number (Re) range of 7007–13,982, the Nusselt numbers of the 60°, 70° and 80° fin angle turbulators are, respectively, compared to the supported plain pipe; increased by 82.09%, 98% and 105.83%. Due to the increase in the blade angle, the maximum thermal performance was obtained as 1.542 for the 80° blade angle turbulator for Re = 12,538. The thermal performance factors of the 80° and 70° blade angle turbulators were found to be 1.048 and 1.039 times higher than the 60° blade angle turbulators, respectively. It was determined that the thermal improvement factor of the 80° blade angle turbulator is 1.008 times higher than the 70° blade angle turbulator. In terms of the second law, the maximum entropy production increase of the finned turbulators compared to the supported plain pipe was 153.96% at Re = 8387, in 3 turbulators with 80° fin angles. It has been determined that 1 turbulator model with 60° blade angles is more advantageous compared to the turbulators with 70° and 80° blade angles, since it produces the lowest entropy. In addition, it has been concluded that the most suitable turbulator model in terms of thermal performance is 3 turbulators with 80° blade angles. Graphic abstract: [Figure not available: see fulltext.]