Fluid Flow and Thermal Characteristics of an Obtuse-Angled Trapezoidal Solar Air Heater Channel With Corner Modifications and Ribs on Absorber Plates

Abstract

In the ongoing research, an endeavor is made to discover the thermal and flow behavior of air flowing through an isosceles obtuse-angled trapezoidal solar air heater (SAH) channel by integrating a couple of geometrical amendments in the flow passage. By amending one or two bottom corners of the simple channel (model 1) from regular sharp to curvatures, two channels, i.e., model 2 and model 3 are generated. Out of models 1–3, the better model is discovered to be model 3, according to the rise in air bulk temperature value. The effect of the corner radius of curvature (5–20 mm) is also investigated in these three models. On the better model 3, rectangular ribs are deployed on few or all absorber plates, consequently, five channels, i.e., models 4–8 are generated. In these models, the rib parameters are adjusted, and advance inquiries are accomplished. 3D computational studies are operated by employing the ansys fluent. Furthermore, experiments are steered to justify the computational findings. The investigations are conceded over Reynolds numbers: 5000–28,000. The impact of operational factors on Nusselt number, friction factor, and channel exit air temperature is examined. The foremost goal of the SAH is to heat the air to a larger extent while passing through the channel. It is identified that the SAH channel model 4 (bottom two corners with a curvature of 20 mm and rectangular ribs on top absorber plate with relative rib height 0.04) is the supreme possibility, displaying temperature augmentation of 32.32% in contrast to the simple trapezoidal channel.