A computational effort was undertaken to study the effect of rounding of protruding edges of rectangular ribs on turbulent heat transfer and pressure drop in a duct. The computations were focused on turbulent flow with Reynolds number ranging from 5000 to 50,000. Three different fluids ― air, water, and ethylene glycol ― were considered in this investigation. This allowed Prandtl number to vary from 0.707 to 150.5. In this study, the edge radius of curvature was varied from zero (sharp edge) to 1/2 of the rib height. The computations were performed using the control-volume approach, SIMPLE algorithm, and QUICK scheme. The results for the round-edge ribs with constant wall heat flux indicated a slight enhancement of the rib-average heat transfer coefficient. The maximum and average enhancements were 8.6% and 2.6%, respectively, with a standard deviation of 2.3% for 75 computational data points. The total rate of heat transfer, however, decreased by 8.6% due to lower surface area of the round-edge ribs. The heat transfer results were correlated in terms of Reynolds number, Prandtl number, and radius of curvature. Pressure drops were also computed and are reported in this paper.
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