Energy storage concentrates on solar air heaters with artificial S-shaped irregularity on the absorber plate

This study utilizes the friction factor as a means to evaluate the impact of the roughness parameter on both heat transfer and pressure drop. This work involves doing an experimental and numerical investigation on the utilization of artificial roughness in solar air heaters situated in outdoor settings. The study examines the effects of using a rectangular S-shaped arrangement of artificial roughness, both in an inline and staggered configuration. The objective of this study is to validate the enhanced thermo-hydraulic performance of solar air heaters using various arrangements of artificial roughness shapes. The parameters considered include the length of the relative roughness (d/H = 1.33), the height of the relative roughness (e/H = 0.271), and the constant distance between S (b/H = 0.667). The Reynolds number is varied within the range of 3000 to 10,000, while the pitch range (p/H) is set to (1.667, 3.33, 5, 6.667) for in-line arrangements and (l/H) is set to (0.8335, 1.666, 2.5, and 3.335) for staggered arrangements. The results show that enhancing heat transfer using an artificial roughness staggered arrangement is the best. The maximum Nusselt number was observed at a dimensionless pitch-to-height ratio of 3.33 for both inline and staggered arrangements, with values of 4.87 and 4.2 times higher than that of the smooth duct, respectively.