Numerical evaluation of the thermal performance of a solar air heater equipped with two different types of baffles.

In the present study, the effect of utilizing two different types of baffles in the channel of the solar air heater is investigated numerically. The studied baffles include angled rectangular baffles and angled V‐shaped baffles, which are mounted on the bottom and top walls of the duct, respectively. Both considered baffles were evaluated separately which the studied parameter in each section was the angular position of baffles. Finally, the best‐obtained results of both sections were compared to each other. The results indicated that in the rectangular model by comparison between 90° model and no baffle, it was found that the pressure drop and average Nusselt number increase 316.67% and 148.15%, respectively at Reynolds number (Re) = 2000. Also, in V‐shaped angled baffles, the thermal efficiency of β = 90°, 60°, 45°, and 30° are 27%, 18%, 13% higher than no baffle channel at Re = 2000, respectively. Furthermore, at low Re (about Re below 300), utilizing baffles into the channel had no effect on the thermal efficiency of the system compared to the no baffle channel. However, at high Re, it was found that the highest thermal efficiency occurred in the model of rectangular baffles with an angle of 90°. [ABSTRACT FROM AUTHOR]