Investigation of Thermal Performance of Solar Air Heater with parabolic Absorber Shapes Using Experimentation & ANSYS Simulations
Abstract
The increasing global demand for clean and sustainable energy has accelerated research on high-performance solar thermal systems. Among these, Solar Air Heaters (SAHs) offer a simple and cost-effective solution; however, their thermal efficiency is strongly influenced by absorber plate geometry. This study investigates the thermal performance of a Solar Air Heater employing parabolic absorber plates with four different configurations: regular inward, regular outward, zigzag inward, and zigzag outward. The performance evaluation was carried out through both experimental investigations and Computational Fluid Dynamics (CFD) simulations using ANSYS Workbench R15.0. The analysis considered inlet and outlet air temperatures, solar irradiance, heat transfer rate, Reynolds number, Nusselt number, and thermal efficiency under operating conditions from 11:00 AM to 3:00 PM. Experimental results demonstrate that the parabolic zigzag (outward) configuration provides the best thermal performance throughout the day due to enhanced airflow turbulence, improved heat transfer, and greater solar energy absorption. At peak solar irradiance (1350 W/m² at 2:00 PM), this configuration achieved the highest experimental thermal efficiency of 28.70%, a heat transfer rate of 75 W/m², and a CFD-predicted efficiency of 31.10%. The CFD results closely agreed with the experimental observations, confirming the reliability of the numerical model with only minor deviations. Comparative analysis further revealed that outward configurations consistently outperform inward configurations, while zigzag profiles provide superior heat transfer characteristics compared to regular profiles. Overall, the parabolic zigzag (outward) absorber geometry proved to be the most effective design for enhancing thermal efficiency and solar energy utilization in solar air heaters. The findings provide valuable guidance for the optimization of absorber plate geometries and support the development of efficient, sustainable, and large-scale solar thermal energy systems.