This investigation integrates experimental and numerical approaches to study a novel solar air heater aimed at achieving an efficient design for a solar collector suitable for drying applications under the meteorological conditions of Iraq. The importance of this investigation stems from the lack of optimal exploitation of solar energy reaching the solar collector, primarily attributable to elevated thermal losses despite numerous designs employed in such solar systems. Consequently, enhancing the thermal performance of solar collectors, particularly those employed in crop drying applications, stands as a crucial focal point for researchers within this domain. Two identical double-pass solar air heaters were designed and constructed for this research. Two types of copper foam sheets with different pore densities, specifically 10 PPI and 40 PPI, were used as absorber plates. The novel solar air heater was compared with a conventional solar air heater equipped with a flat absorber plate based on thermal performance. The effects of the mass flow rate, the air gap of the solar collector, and solar irradiation were examined on various parameters, including the outlet air temperature, solar collector efficiency, and pressure drop across the solar collectors. The results demonstrated that the double-pass solar air heater equipped with a 10 PPI porous absorber plate exhibited superior thermal performance compared to both the double-pass solar air heater with a 40 PPI absorber plate and the conventional absorber plates. Consequently, it can be considered suitable for drying applications. Furthermore, a comparison of the experimental findings with the results obtained from previous studies showed a good agreement.
