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http://dx.doi.org/10.9726/kspse.2012.16.6.030

Effect of Rib Height on Turbulence and Convective Heat Transfer  

Nine, Md.J. (Department of Energy & Mechanical Engineering, GyeongSang National University)
Kim, S.J. (Department of Energy & Mechanical Engineering, GyeongSang National University)
Jeong, H.M. (Institute of Marine Industry, GyeongSang National University)
Chung, H.S. (Institute of Marine Industry, GyeongSang National University)
Rahman, M.Sq. (Dept. of Agricultural & Industrial Engineering, Hajee Mohammad Danesh Science & Technology University)
Publication Information
Journal of Power System Engineering / v.16, no.6, 2012 , pp. 30-37 More about this Journal
Abstract
Effect of rib heights is found as significant parameter to enhance convective heat transfer performance under laminar and low turbulent regime. Circular ribs with different ribheight to channel height ratios, e/H = 0.05, 0.1, 0.15, are fabricated over the copper substrate respectively in a rectangular duct having 7.5 cross sectional aspect ratio. Only one rib pitch to rib height ratio (P/e = 10) has been chosen for all different height ribs. The result shows that the arithmetic average of turbulence intensity decreases with decreasing roughness height calculated between two ribs under laminar and low turbulent region. It occurs because the area of recirculation and reattachment zone also decreases with decreasing rib height. Optimum thermal enhancement factor is derived by 0.1 rib height to channel height ratio under low turbulent region but 0.15 rib height to channel height ratio gives maximum subjected to laminar flow.
Keywords
Rectangular duct; rib height; Friction factor; Heat Transfer;
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