EXPERIMENTAL AND CFD ANALYSIS OF A CURVED-CHANNEL SOLAR AIR HEATER WITH INTEGRATED FINS AND BAFFLES

In this experimental and numerical work, thermohydraulic performance of curved-channel solar air heater assisted with finned absorber and baffled back plates is discussed. The study utilizes computational modeling and simulation technique, firstly to analyze the effect of baffle design and geometrical parameters on fluid dynamics, heat transfer, and the system's thermohydraulic efficiency. Secondly, the combined effect of baffles and fins on the thermohydraulic efficiency is analyzed. The range of geometrical and flow parameters, viz., the baffle height (0.0075 ≤ <i>h<sub>b</sub></i> ≤ 0.015 m), fin height (0.0075 ≤ <i>h<sub>f</sub> </i>≤ 0.015 m), pitch (0.05 ≤ <i>p</i> ≤ 0.1 m), baffle inclination angle (30° ≤ α ≤ 90°), and the Reynolds number (2000 ≤ Re ≤ 24,000) is selected and the optimum values are revealed on the basis of thermohydraulic efficiency. The optimization findings indicated that the optimal values of Re = 12,000, α = 30°, <i>h<sub>b</sub></i> = <i>h<sub>f</sub></i> = 0.0075 m, and <i>p</i> = 0.1 m achieved the maximum thermohydraulic performance. The results showed that the presence of fins and baffles significantly increased fluid mixing at a Reynolds number of 12,000 that consequently increases the thermal performance of the system by introducing mechanisms such as vortex generation, impinging streams, and interrupted thermal boundary layers.