Effect of various configurations of swirl generator system on the hydrothermal performance of the flat-plate solar collector

This is a numerical study that analysis the heat extraction potential of solar collector tubes by assembling a couple of nozzles at the sealed end of the pipe to make swirl flow. Swirl flow intensifies the turbulence rate which augments heat transfer by ruffling the boundary layer. To this end, several decisive factors including nozzle angle (A: 30 degrees, 45 degrees, 60 degrees, 90 degrees), tube diameter (D: 20 mm, 50 mm), nozzle edge size (N: 6.25, 12.5, 25 mm (for D50) and N: 2.5, 5, 10 mm (for D20)), and mass flow rate (M: 0.1, 0.5, 1 kg/s (for D50) and M: 0.04, 0.2, 0.4 kg/s (for D20)) were considered. Results demonstrated that all of the models of class "A.../D20/N.../M..."had higher heat extraction potential but lower friction factor compared with "A.../D50/N.../M...". Maximum and minimum D20/N2.5/M0.400 and "A30/D50/N25/M0.100. The created friction factor by class "A.../D50/N .../M..."is higher than class "A.../D20/N.../M...". The highest friction factor is 3.51 ("A90/D 20/N2.5/M0.0400) and the lowest friction factor is 0.019 ("A30/D20/N2.5/M0.200). Overall, for all cases, class "A.../D50/N.../M.. ."bear the higher TPF compared with class "A.../D50/N.../M ..."so that the greatest and lowest values of TPF are 5.09 and 0.49 achieved by "A30/D50/N6.2 5/M100 and "A90/D20/N5/M0.400, respectively. (c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).