Effective permeability and thermal conductivity of open-cell metallic foams via homogenization on a microstructure model

To predict effective thermal conductivities and permeabilities of open-cell foams, produced by a SlipReactionFoamSintering (SRFS)-process, a multiscale approach based on the homogenization method is applied. This formulation allows to calculate effective aerothermal properties by solving either special thermal or Stokes flow problems on a unit cell. Starting from a detailed foam description by tomographic images, 3D microstructure models of the SlipReaction (SR)-foam are generated by combining spectral analyses with a specific mesh generation. Effective thermal conductivities of an Inconel foam sample are predicted with different FE discretizations by the homogenization procedure and compared with the experimental results, measured by the transient plane source technique. Effective Darcy permeabilities are evaluated in the foam center and compared with experimental pressure drop measurements. Moreover, permeability predictions of the unit cells with extremal porosity allow to measure the permeability scatter of the Inconel SR-foam sample.