A Review on Roughened Solar Air Heater for Heat Transfer and Thermal Efficiency

Abstract

The use of artificial roughness on the absorber plate is the most effective technique to enhance the thermal performance of solar air heaters. Experimental investigation of distinct roughness geometries shows that the enhancement in the rate of heat transfer is accompanied by considerable rise in temperature. In this paper some distinguished roughness geometries have been compared on the basis of heat transfer rate and thermal performance. The objective of  this paper is to review the various studies for different artificial roughness elements used to enhance the heat transfer rate. Correlations developed on the basis of experimental results for heat transfer and friction factor of solar air heater ducts by various investigators. These correlations are used to predict the thermal performance of solar air heaters having roughened ducts. The different type of roughness geometries are taken for study as given in the table.

Keywords: Artificial roughness, effective efficiency, heat transfer coefficient, roughness  geometries, solar air heater and thermal performance

Cite this article:

Nitesh Kumar, Singh KDP, Sharma SP. A Review on Roughened Solar Air Heater for Heat Transfer and Thermal Efficiency. Journal of Experimental & Applied Mechanics (JoEAM). 2015; 6(1): 49–56p.