COMPARATIVE STUDY OF SOLAR AIR HEATER WITH FLUID FLOW CHANNEL ABOVE & BELOW A WAVY-SHAPED ARCHED ABSORBER PLATE

Solar thermal energy is abundant and freely available, making it a valuable resource for sustainable energy solutions.Systems like solar air heaters are commonly used for both space heating and drying applications.However, the overall thermal performance of solar air heaters is often limited by inefficient heat transfer between the absorber plate and the air.In this study, the fabrication and performance analysis of a solar air heater with wavy absorber plate has been carried out.The study presents a comparative analysis of the thermal performance of a solar air heater with two distinct fluid flow channels: one between the glazing and the absorber plate, and the other between the absorber plate and the bottom surface.The wavy design of the absorber plate promotes air turbulence and vortex formation, disrupting the laminar sub-layer near the absorber surface and thereby enhancing heat transfer within the system.Four configurations were examined: fluid flow in the upper channel with and without an arch in the absorber plate, and fluid flow in the lower channel with and without the arch.During the experiments, a constant air flow rate of 5 m/s was maintained using a blower.Results indicated that the temperature difference achieved with the fluid flowing above the absorber plate was higher than that of the fluid flowing below by approximately 10-20%.However, when the absorber plate was arched, there was a notable improvement in the performance of the fluid passage below the absorber plate.