Overall Heat Transfer Enhancement of Triangular Obstacles

Abstract

In this study, the effects of equilateral triangular bodies placed in the channel on heat transfer and pressure drop characteristics were examined numerically. Reynolds number varied from 5000 to 10,000. The effects of the blockage ratio at constant edge length (B=20 mm) and Reynolds number of triangular bodies were investigated. An RNG based k-ε method was used and a constant surface temperature was applied to the bottom wall. The numerical results were presented with respect to temperature contours, local and mean Nusselt number, local and mean surface friction factor changes and heat transfer enhancement ratios. The results showed that the presence of the equilateral obstacles in the flow field enhanced the heat transfer. Temperature distributions behind the bodies were affected by the position of the triangles and the Reynolds number and changed greatly in the vertical direction along the x distance beyond the bluff bodies. The intensity of the oscillations decreased with the increase of the Reynolds number. It was observed that for all cases overall heat transfer enhancement was provided. It was found that the highest values of OHTE were reached at  W/B=0 and Re=5.0 and lowest were at W/B=1 and Re=10.0.