A Comprehensive Review of Recent Trends in Augmentation Heat Transfer Solar Air Heaters Using Arc-Shaped Ribs

The solar air heater is a simple means to use abundant available solar energy. Solar air heaters have low thermal efficiency because air is a heat transfer medium. The passive boundary layer must be broken by creating turbulence over the surface to improve heat transfer. To accomplish it, many methods were used, like creating surface roughness by putting ribs, fins, or dimples over the surface. Over the period, many types of ribs were used to create surface roughness and a parametric study of heat transfer from the surface was done. The present study reviews arc-shaped ribs for various configurations used by many researchers and analyzes the effect of flow parameters. Comparison based on investigation of heat transfer coefficient at different Reynold numbers considering parameters such as Nusselt number and friction factor was performed.