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：2010
卷号：1
期号：6
页码：987-998
出版社：International Energy and Environment Foundation (IEEF)
摘要：Artificial roughness in the form of repeated ribs is generally used for enhancement of heat transfer heated surface to the working fluid. In the present work experimental investigations has been carried out to study the effect of a gap in the inclined rib on the heat transfer and fluid flow characteristics of heated surface. A rectangular duct of aspect ratio of 5.83 has been used to conduct experiments on one rib roughened surface. Experimental data have been collected to determine Nusselt number (heat transfer coefficient) as a function of roughness and flow parameters in the form of repeated ribs. In order to understand the mechanism of heat transfer through a roughened duct having inclined rib with and without gap, the detailed analysis of the fluid flow structure is required. Therefore the detailed velocity structures of fluid flow inside a similar roughened duct as used for the heat transfer analysis were obtained by 2-Dimensional Particle Image Velocimetry (PIV) system and the heat transfer results were correlated with the flow structure. It was found that inclined rib with a gap (inclined discrete rib) had better heat transfer performance compared to the continuous inclined rib arrangement. Further the inclined discrete rib with relative gap width (g/e) of 1.0 gives the higher heat transfer performance compared to the other relative gap width.
