Reduced material model for closed cell metal foam infiltrated with phase change material based on high resolution numerical studies

• Closed cell metal foam sandwich structures were investigated.
• High resolution numerical studies were conducted using CT scan data.
• A reduced model for use in commercial FE software reduces needed degrees of freedom.
• Thermal inertia is increased about 4 to 5 times in PCM filled structures.
• The reduced material model was verified using experimental data.

The thermal behaviour of closed cell metal foam infiltrated with paraffin wax as latent heat storage for application in high precision tool machines was examined. Aluminium foam sandwiches with metallically bound cover layers were prepared in a powder metallurgical process and cross-sectional images of the structures were generated with X-ray computed tomography. Based on the image data a three dimensional highly detailed model was derived and prepared for simulation with the adaptive FE-library AMDiS. The pores were assumed to be filled with paraffin wax. The thermal conductivity and the transient thermal behaviour in the phase-change region were investigated. Based on the results from the highly detailed simulations a reduced model for use in commercial FE-software (ANSYS) was derived. It incorporates the properties of the matrix and the phase change material into a homogenized material. A sandwich-structure with and without paraffin was investigated experimentally under constant thermal load. The results were used to verify the reduced material model in ANSYS.