High resolution microtomography-based CFD simulation of flow and heat transfer in aluminum metal foams

The necessity for devising more effective heat transfer technologies and innovative materials, capable of increasing performances while keeping power consumption, size and cost at reasonable levels, is well recognized. Under this prospect, metal foams are good candidates for improving the thermal efficiency of heat transfer devices and allowing, at the same time, the use of smaller and lighter equipments. For design purposes, the proper characterization and quantification of transport and thermal properties of metal foams is fundamental but far from simple. This lack of information constitutes a fundamental limit in the employment of metal foams in practical and industrial applications. Nowadays, besides classical transport models and correlations, computational fluid dynamics (CFD) at the pore scale, although challenging, are becoming a promising approach for recovering the transport properties of the medium, especially if coupled with a realistic description of the foam structure. In order to precisely describe the microstructure of the foams, a 3D approach based on the X-ray computed microtomography (m-CT) technique can be adopted. In this work, the results of high resolution m-CT-based CFD simulations, performed on three different open-cell aluminum foams samples, will be illustrated. The results demonstrate that open-cell aluminum foams are effective means for enhancing heat transfer. Moreover, the procedure proved that m-CT is a valid tool for capturing the peculiar details of the foam structure, thus to overcome the limits associated to the use of economical, but simplified, geometric models.