Enhanced Heat Transfer Performance in a Solar Air Heater using discrete V-Rib Geometry with Gap

Abstract

Abstract Solar air heater (SAH) have emerged as promising technology for harnessing solar energy in a sustainable and environmentally friendly manner. Numerous techniques for enhancing heat transfer methods have been investigated to improve thermal performance. This study investigated how discrete V rib coarseness effect the performance of SAH. The experiments were conducted under different operating conditions, including rib pitch-to-height ratios (p/e) of 8, 10, and 12, an angle of inclination of 60 degrees, width to height of duct (W/H) 8, gap width to depth 4, Centre distance between two successive ribs of 0.5, number of gaps on each side of 1 and Reynolds number of 4000 to 145000. Experimental data indicated that the SAH equipped with the discrete V-rib geometry and gap achieved higher heat transfer rates compared to traditional SAH designs without this feature. In this case, the Nusselt number (Nu), Thermo-hydraulic performance parameters (THPP) and friction factor (f) increased by 3.62, 3.22, and 2.85, respectively, compared to a flat plate. These values indicate the improvements achieved by the artificial rib coarseness in enhancing heat transfer compared to a flat surface. Furthermore, study demonstrated that the new discrete V-rib geometry with a gap outperformed to existing designs.