Experimental analysis and thermal management of solar air heater roughened with sine wave baffles

Abstract

In the present study, a thermo-hydraulic performance (THP) of solar air heater (SAH) has been assessed by placing sine wave-shaped baffles on the heat-absorbing surface. The experiments have been performed by varying Reynolds number ([Formula: see text]) ranging from 3000-18,000, relative pitch ([Formula: see text]) ranging from 8 to 14, relative height ([Formula: see text]) ranging from 0.4 to 0.55, relative baffle length [Formula: see text] ranging from 0.054 to 0.081 and angle of attack(α) ranging from 10° to 45° while the duct aspect ratio has been kept fixed at 12. The best set of geometric parameters has been decided based on Nusselt number [Formula: see text] and friction factor [Formula: see text] characteristics of the roughened SAH and compared with the smooth surface SAH, under analogous experimentation conditions. The cost analysis has also been performed and results revels that roughened SAH is more cost-effective than smooth SAH. The correlation for Nusselt number [Formula: see text], friction factor [Formula: see text], and thermo-hydraulic performance parameters (η) have been developed using regression analysis and found an average deviation of ±9.15%, ±7%, and ±9.2% respectively, from experimental results.