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An experimental investigation on the heat transfer effectiveness of solid and slit ribs mounted on the bottom surface of a rectangular channel has been carried out at Reynolds numbers of 13400, 22600, 32100 and 40800. The rib height to hydraulic diameter ratio (e/D h)set during experiment is equal to 0.0624. The surface Nusselt number results from transient liquid crystal thermography are presented. The heat transfer enhancement performance analysis has been carried out using entropy generation principle. The slit rib is superior to solid rib from both heat transfer augmentation and pressure penalty point of view. The performance of the slit rib is a function of the open area ratio (β) and the location of the slit (b) from the bottom test surface. The optimum open area ratio is 20% and the slit located symmetrically from the top and bottom surface of the rib is the optimum location of the slit. The heat transfer augmentation of the slit rib (β=20%) is 61% in comparison to 40% for the solid rib at Re=32100 and the pressure penalty for the slit rib is 7% lower than the solid rib. The entropy generation for the slit rib is 33% less than that of the solid rib.
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Pradipta Kumar Panigrahi: He received his B.S. (Honors) degree in Mechanical Engineering from UCE Burla, Orissa. He received his M.S. in Mechanical Engineering and Computer Science and his Ph.D. in Mechanical Engineering from Lousiana State University, Baton Rouge, USA. Currently he is working as an Assistant Professor in the Mechanical Engineering Department, IIT Kanpur, India. He visited JAPAN from January 2001 to July 2001 for a period of six months under BOYSCAST fellowship. His research interests are optical techniques, heat transfer enhancement, soft computing based modeling and control and turbulence.
Andallib Tariq: He received his B.E degree in Mechanical Engineering from Bangalore University and subsequently completed MBA from Bihar University. Further he studied in Mechanical Engineering and received his M.Tech from Indian Institute of Technology, Kanpur, India. He is currently pursuing Ph.D. at IIT Kanpur. His research interests are experimental fluid mechanics, turbulence, flow visualization and heat transfer enhancement.
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Panigrahi, P.K., Tariq, A. Liquid crystal heat transfer measurements in a rectangular channel with solid and slit rib. J Vis 6, 407–416 (2003). https://doi.org/10.1007/BF03181747
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DOI: https://doi.org/10.1007/BF03181747