@ARTICLE{Kumar_Dhananjay_Heat_2023, author={Kumar, Dhananjay}, volume={vol. 44}, number={No 1}, journal={Archives of Thermodynamics}, pages={63-87}, howpublished={online}, year={2023}, publisher={The Committee of Thermodynamics and Combustion of the Polish Academy of Sciences and The Institute of Fluid-Flow Machinery Polish Academy of Sciences}, abstract={The present paper describes the experimental analysis of heat transfer and friction factor for glass protected three-side artificially roughened rectangular duct solar air heaters (SAHs) having an arrangement of multiple-v and transverse wires (top wall multi-v and two side walls transverse) under the absorber plate, and compares their performance with that of one-side roughened solar air heaters under similar operating conditions. The investigated three-side solar air heaters are characterized by a larger rate of heat transfer and friction factor as compared to one-side artificially roughened SAHs by 24–76% and 4–36%, respectively, for the identical operating parameters. The air temperature below the three-side rugged duct is by 34.6% higher than that of the one-side roughened duct. Three-side solar air heaters are superior as compared to one-side artificially roughened solar air heaters qualitatively and quantitatively both.}, type={Article}, title={Heat transfer and friction characteristics in three-side solar air heaters with the combination of multi-v and transverse wire roughness}, URL={http://journals.pan.pl/Content/127281/PDF/art04_int.pdf}, doi={10.24425/ather.2023.145877}, keywords={Absorber plate, Fluid flow, Heat transfer, Solar air heater, Reynolds number, Relative roughness height}, }