Assessment of Performance Characteristic of Solar Air Heater with Assorted Geometries - A Review

Artificial roughness is an efficient way for increasing the heat transfer rate in solar air heater with the\ud corresponding improvement in its thermal performance. A viscous sub-layer is responsible for the low heat\ud transfer coefficient between absorber plate and flowing air. Repeated ribs in form of artificial roughness are an\ud effective way to increase the heat transfer rate and improving the performance of solar air heater. Artificial\ud roughness of the absorber plate is much economical and effective way to improve the thermal performance of\ud solar air heater. Several investigators have done various investigations to improve heat transfer coefficient with\ud little penalty of friction factor. They have also developed different correlation for heat transfer coefficient and\ud friction factor. The correlations developed for heat transfer and friction factor by various investigators have been\ud reviewed and presented