Study of Performance Enhancement of Single and Double Pass Solar Air Heater with Change in Surface Roughness

Abstract The performance of Solar Air heaters can be enhanced by placing ribs of different geometries over the absorber plate which increases turbulence and thereby increasing its heat transfer and friction factor characteristics. It has been reported by various researchers that Double pass solar air heaters are more efficient than single pass solar air heaters in terms of its Thermal performance. It is also reported that using discrete ribs over the absorber plate in place of continuous ribs gives more heat transfer. The present paper gives us the details of various artificial roughness provided over the absorber plate to increase turbulence. This paper gives a brief overview of various researches done on Single as well as Double pass solar air heaters in terms of its Thermal and Thermohydraulic efficiencies along with Nusselt Number and Friction Factor enhancement.