A numerical investigation of augmented heat transfer in rectangular ducts with ribs

Abstract

The application of roughness structure of ribs inside a smooth channel is one effective way of heat transfer augmentation, but the accompanied pressure drop could be high. A novel V-rib design with branches was introduced and numerical simulations on the thermo-fluid impact of heat transfer and pressure drop were investigated. The parameters of investigation include the branching number and the pitch ratio of the V-ribs. It appears that increasing the relative pitch ratio serves to improve the overall performance of a roughened channel. The effect of the branching number is only experienced at low pitch ratio. At high pitch ratio, varying the branching number only serves to lower the pressure drops. Optimization was found at the branching number of 6 and the relative pitch ratio of 15. At optimal conditions, the Nusselt number ratio, friction factor ratios, and the thermohydraulic performance were 2.15, 2.85, and 1.39 times the plane channel, respectively.