COMPUTATIONAL INVESTIGATION OF THERMAL PERFORMANCE OF SOLAR AIR HEATER HAVING ROUGHNESS ELEMENTS AS TRANSVERSE WIRE ON THE TWO SIDE ABSORBER PLATE

An Analytical investigation has been carried out to study the heat transfer and friction characteristics by using a transverse wire on the absorber plate of a solar air heater. The Analytical investigation consist the Reynolds number (Re) ranges from 3000 to 14 000, relative roughness pitch (p/e) 10–30 and relative roughness height (e/D) 0.0135-0.0225. The effect of these parameters on the heat transfer coefficient and friction factor has been discussed in the present paper and correlations for Nusselt number and friction factor has been developed within above limits. A procedure to compute the thermal efficiency based on heat transfer processes in the system is also given and the effect of these parameters on thermal efficiency has been discussed .transverse wire have been used to enhance heat transfer coefficient. A Matlab code has been encoded for the analysis of thermal efficiency through iteration method. Results shows that the accuracy of thermal efficiency are 78% for this roughened solar air heater. By providing artificial roughness it has been concluded that there is an improvement of heat transfer coefficients which results increase in pumping power, pressure drop and high value of thermal performance.