Enhancement of heat transfer from a horizontal cylinder wrapped with whole and segmented layers of metal foam

Abstract

In the present study, the flow and heat transfer characteristics from a horizontal cylinder in crossflow wrapped with whole and segmented layers of metal foams are investigated. High porosity and thermal conductivity metal foam layers are tested with two different thicknesses. The horizontal cylinders are heated with a uniform heat flux and forced convection tests are conducted for Reynolds number range of 7500 – 18000. The angle at which the metal foam segmented layers are positioned against the incoming flow is varied to study the effect of the angle of incidence on the performance. The heat transfer coefficient and pressure drop are measured in order to determine the overall performance factor which relates the enhancement in heat transfer with the pressure drop augmentation. The experimental results showed that all metal foam configurations outperformed the bare cylinder case. The whole layer configuration showed the highest heat transfer enhancement as opposed to the segmented layer case, but with a higher pressure drop. However, the segmented metal foam layer configuration, at an optimum angle of incidence, provided the best heat transfer enhancement with a lower pressure drop, signifying the highest overall performance factor.