Thermohydraulic Performance Evaluation of Roughened Absorber Plate Having Continuous Transverse Sinusoidal With Protrusion Ribs

Abstract The thermohydraluic performance (THP) evaluation of roughened absorber plate in the form of continuous transverse sinusoidal with protrusion ribs (CTSPR) of a solar air heater (SAH) was investigated numerically and experimentally. The performance metrics Nusselt number (Nu), friction factor, and THP have been assessed for roughness pitches of 10 mm, 14 mm, and 18 mm, roughness height near the sublayer thickness of 1 mm, and Reynolds numbers ranging from 4000 to 15,000. Additionally, the present model (CTSPR model) has been also compared with the past research model i.e., continuous transverse sinusoidal rib (CTSR model) in the graphical form. The effect of various paths of fluid, temperature, and vortexes on heat transfer has been explained in the present research. Observations indicate that the thermohydraluic performance parameters of the CTSPR model are higher than those of the CTSR model across the investigated parameter range. An ideal value of THP has been achieved with a roughness pitch of 10 mm, a roughness height of 1 mm, and a Reynolds number of 4000. Validation of computational results of the optimum model of the CTSPR model is conducted by comparing them with experimental outcomes. The experimental testing results of the Nusselt number and the friction factor exhibit individual variations of 6.36% and 3.97%, respectively, from computational results.