Performance of a single row heat exchanger with metal foam covered tubes

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.

Open cell metal foam Is a novel engineering material that offers an Interesting combination of materials properties from a heat exchanger point of view such as a high specific surface area, tortuous flow paths for flow mixing and low weight A new heat exchanger design with metal foams Is studied In this work, aimed at low airside pressure drop. It consists of a single row of aluminum tubes covered with thin layers (4-8 mm) of metal foam. Through wind tunnel testing the Impact of various parameters on the thermo-hydraulic performance was considered, Including the Reynolds number, the tube spacing and the foam height The results Indicated that providing a good metallic bonding between the foam and the tubes can be achieved, metal foam covered tubes with a small tube spacing and small foam heights potentially offer strong benefits at higher air velocities (> 4 m/s) compared to helically finned tubes. The bonding was done by conductive epoxy glue and was found to have a strong Impact on the final results, showing a strong need for a cost-effective and efficient brazing process to connect metal foams to the tube surfaces.