Turbulent heat transfer and pressure loss in a square channel with discrete broken V-rib turbulators

Turbulent periodic flow, heat transfer, friction loss and thermal enhancement characteristics in a three-dimensional horizo- ntal square channel with broken V-ribs (B-VR) are numerically investigated. The computations are based on the finite volume method, and the SIMPLE algorithm with QUICK scheme is implemented. The B-VR were installed on both sides of a plate which was diagonally placed in a square channel to produce longitudinal vortex flows through the tested section. Effects of different open corner ratios (d/H = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) on heat transfer and pressure loss in the channel and the results of the B-VR are studied. The pitch ratio (PR= p/H) and blockage ratio (BR = p/H) of B-VRs were fixed at 1.0 and 0.15, respectively. As compared with the channel without V-rib, the one with B-VRs possessed considerably higher heat transfer and friction loss. It is observed that apart from the rise of Reynolds number, the reduction of the open corner ratios leads to an increase in the Nusselt number and friction factor due to the weaker turbulence and lower resistance to the flow. According to the computational results for B-VRs, the optimum thermal enhancement is found at d/H = 0