Arc-shaped ribs in solar air heaters, owing to their geometry, have the potential to generate secondary flows and enhance flow mixing, thereby contributing to the enhancement of heat transfer. In this study, the effects of vertically placed convex and concave fully arc-shaped and discrete arc-shaped ribs on thermal performance and entropy generation in solar air heater (SAH) flow are investigated, with the aim of determining the optimal SAH configurations. In this study, the radius of the arc-shaped ribs was set to R = 50 mm and their height to Hr = 75 mm, and for discrete type ribs, the gap was chosen as 3 mm. Numerical analyses were conducted within the Reynolds number range of 5000–20000. According to the obtained results, the highest thermal enhancement factor (TEF) value of 3.23 was found for the CXFA-SAH configuration. In terms of entropy generation ratio, the lowest value was determined to belong to the CXDA-SAH configuration, at 0.6038.
Mehmet Sener (Sat,) studied this question.