A Review on Analysis of solar air heaters having Artificial Roughness

Solar air heater is the cheapest and extensively used solar energy collection device for dryingof agricultural products, space heating, seasoning of timber and curing of industrial products.The use of an artificial roughness on a surface is an effective technique to enhance the rate ofheat transfer to fluid flow in the duct of a solar air heater. Use of artificial roughness in solarair heater has been topic in research for the last thirty years. In the present article an attempthas been made to present holistic view of different kinds of roughness geometry used forcreating artificial roughness in solar air heater for performance enhancement by experimentalapproaches. In this article thirty eight experimental studies have been reported on solar airheater, roughened with different kinds of roughness geometry. . However, no comprehensivecomparative study has been carried out or found in the literature so far, in order to investigatethe relative performance of different types of artificially roughened solar air heater. Theobjective of this article is to perform such a study. Correlations for heat transfer and frictionfactor, developed by various investigators for artificially roughened solar air heaters havebeen reported in this report. The effects of various rib parameters on heat transfer and fluidflow processes are also discussed.