期刊名称：International Journal of Energy and Environment
印刷版ISSN：2076-2895
电子版ISSN：2076-2909
出版年度：2012
卷号：3
期号：6
页码：967-976
出版社：International Energy and Environment Foundation (IEEF)
摘要：An experimental investigation has been carried out to see the effect of roughness element on heat transfer and friction factor on the absorber plate of the solar air heater. The roughness provided is in the form of protrusions which are arranged in an arc pattern. This paper presents an investigation to study the effect of protruded geometry on heat transfer coefficient and friction factor in an artificially roughened solar air heater duct. The pair of protrusion geometry arc angle (α) of 45o is mounted on the test section of duct to create a longitudinal flow through test section. Measurements are carried out for rectangular duct which has aspect ratio (W/H) of 11, relative roughness pitch (P/e) in the range of 12-24, relative roughness height (e/D) of 0.03, ratio of height of protrusion to print diameter (d) of 0.3° and Reynolds number (Re) ranges from 3600-18100.The results obtained for various relative roughness pitch (P/e) has also been compared with smooth one. And on comparison to smooth duct, the roughened duct enhances the heat transfer and friction factor by 2.96 and 2.73 times.
