An experimental study on open cell metal foam as extended heat transfer surface

• Copper foams with varying PPI experimentally tested for thermo-hydraulic behaviour.
• Modelling of metal foams analogous to that of ordinary fins with cross-connections.
• Foam matrix subjected to constant wall temperatures at one or both ends.

Experiments have been performed with high porosity, open cell copper foam blocks sandwiched between plates at constant temperature. Convective air passing through the foam carries the heat being conducted through the plate and foam matrix. Foam acts as an extended heat transfer surface adhered to the primary one (plate). Air, entering the foam at uniform temperature, leaves with a spatial temperature variation. Mathematical modelling with the repetitive “simple cubic” structure representing metal foam has been used to explain the exit air temperature variations. Governing foam heat transfer equations and the resulting solution have strong resemblances with those of the conventional fins with appropriate corrections required for the interconnected foam structure. Good agreement between the experimental data and theoretical prediction has been observed. The proposed model is simple yet effective. One can avoid rigorous numerical calculations necessary to analyse heat transfer in metal foam used as extended heat transfer surfaces in many engineering applications such as heat sinks and heat exchangers.