Turbulent flow characteristics and heat transfer enhancement in a rectangular channel with elliptical cylinders and protrusions of various heights

This numerical study investigates turbulent flow characteristics and heat transfer augmentation in a rectangular channel with elliptical cylinders and protrusions. The height of protrusions is changed to quantify interactions with surrounding elliptical cylinders. Flow structures, temperature distributions, and heat transfer characteristics are obtained with a standard k − ε turbulence closure model. Cases are run at Reynolds numbers of 15,000 and 20,000. Combinations of protrusion and elliptical cylinder geometries give higher heat transfer rates than a case without protrusions. Additionally, Nusselt numbers increase with increases in height of protrusions and an optimum height-to-footprint diameter ratio is found.