An Experimental and Numerical Thermal Flow Analysis in a Solar Air Collector with Different Delta Wing Height Ratios

This study conducts both numerical and empirical assessments of thermal transfer and fluid flow characteristics in a Solar Air Collector (SAC) using a Delta Wing Vortex Generator (DWVG), and the effects of different height ratios (R_h = 0.6, 0.8, 1, 1.2 and 1.4) in delta wing vortex generators, which were not considered in the earlier studies, are investigated. Energy and exergy analyses are performed to gain maximum efficiency. The Reynolds number based on the outlet velocity and hydraulic diameter falls between 4400 and 22000, corresponding to the volume flow rate of 5.21–26.07 m³/h. It is observed that the delta wing vortex generators with a higher height ratio yield maximum heat transfer enhancement and overall enhancement ratio. The empirical and numerical findings demonstrate that the exergy and thermal efficiencies decline in a specific range. The Nusselt number, pressure drop, energy, and exergy efficiencies enhance with rising Reynolds number, although the friction coefficient diminishes. The maximum heat transfer enhancement is 57%. According to the evaluation of exergy efficiency, the greatest efficiency of 31.2% is obtained at R_h = 1.4 and Reynolds number 22000.