Augmentation on Heat Transfer and Friction Factor in Three Sides Solar Air Heaters Having an Arrangement of Multi-V and Transverse Wire Roughness on the Absorber Plate

Abstract

This paper present the experimental inquiry on heat transfer and friction features enrichment adopting new-fangled of three side’s synthetically rugged rectangular duct solar air heaters (SAHs). The roughened rectangular SAH ducts has been an arrangement of multi-v and transverse wire (top wall multi-v and two side walls transverse) covered with glass on three sides. It has various appliances such as crop drying, seasoning of timber, space heating, industrial purpose, etc. The rectangular duct used has a width to height ratio, W/H, equal to 8, relative raggedness pitch, P/e, wide-ranging from 10 - 25, relative raggedness height, e/D, varied from 0.018 – 0.042 and flow Reynolds number, Re, occupied from 3500 – 12,000 for fixed values of relative raggedness width, W/w, of 6 and an angle of attack, 𝛼, equal to 60°. The heat transmission and friction features of this roughened duct is compared with plane ones under identical working conditions. The maximum augmentation in heat transmission and friction feature is identified to be 6.42 and 6.44 times over the smooth duct respectively. The enhancement in air temperature streaming under three side’s synthetically rugged SAH duct is found to be 54.47% more than that of the smooth one. Three side’s artificially rugged rectangular duct SAHs are preferable over plane ones collectively and tentatively