Abstract :
In this work, results of an experimental investigation of the effect of geometrical parameters of Multi v-shaped ribs with gap on heat
transfer and fluid flow characteristics of rectangular duct with heated plate having rib roughness on its underside have been reported. The
range of parameters for this study has been decided on the basis of practical considerations of the system and operating conditions of
solar air heaters. The experimental investigation encompassed the Reynolds number (Re) range from 2000 to 20,000, relative width ratio
(W/w) of 6, relative gap distance (Gd/Lv) of 0.24–0.80, relative gap width (g/e) of 0.5–1.5, relative roughness height (e/D) of 0.043,relative
roughness pitch (P/e) of 10, angle of attack (a) of 60 . The maximum enhancement in Nusselt number and friction factor is observed to
be 6.32–6.12 times of that of the smooth duct, respectively. The thermo-hydraulic performance parameter is found to be the best for the
relative gap distance of 0.69 and the relative gap width of 1.0.
2012 Elsevier Ltd. All rights reserved.
