Enhancement of Heat Transfer in Solar Air Heater Using Artificial Roughness: A Review

Thermo hydraulic performance of a solar air heater can be improved by enhancing heat transfer between the duct plate and the air. Generally heat transfer enhancement technique categories as Active and Passive technique. Passive technique comprises of adding “Artificial Roughness” that enhances heat transfer by breaking thermal resisting, laminar sub layer. Various roughness geometries with their parameters and correlations are made available by investigators for studying heat transfer enhancement and fraction factor. Present paper is a tabulated review of all these geometries, parameters and correlation for suitable selection.