Open cell aluminum foam applied in an automotive heat exchanger

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.Heat transfer with open cell aluminium foam has been studied mainly for electronics cooling. In this contribution, we want to show the possibilities of using this foam in an automotive heat exchanger application. More specific, a water cooler for a high performance race car was build and tested. Bonding of the foam was done with an alumina particles enriched epoxy, which introduces an extra thermal resistance compared with brazing technology. Furthermore, it is known that pressure drop of open cell foam versus louvered fins, is rather at the high end. To overcome these issues, use was made of the relatively more isotropic nature of the foam compared to finned structures. This resulted in a completely different shape of the cooler when comparing with conventional rectangular coolers. As a result, heat exchanging surface area could be increased dramatically. The drawback is an increased complexity to design such coolers. Preliminary results have shown a 50% increase of heat transfer compared with a conventional cooler mounted at the same position. This was measured during a wind tunnel test campaign and confirmed by real-time measurements when driving the car. Recalling that the cooler was manufactured with a single epoxy, it is believed that performance can be augmented significantly by a metallic bonding.