Thermal and Thermo Hydraulic Performance of Three Sides Artificially Roughened Solar Air Heaters

The experimental results on Stanton number, friction factor and thermal performance of three sides artificially roughened and glass covered solar air heaters with those of smooth and three sides glass covered solar air heaters have been represented. Results show that the values of Stanton number are more in three sides roughened one, leading to an increase of 53% to 57% in thermal performance as compared to three sides glass covered smooth one. However, friction factor increases by 28% to 38%. The effect of roughness and flow parameters (p/e, e/D, Re) on heat transfer, friction factor and thermo hydraulic performance has been shown and discussed. The optimal thermo hydraulic performance of such solar air heaters has been achieved at an optimal value of optimization parameter, .