On the porosity-dependent permeability and conductivity of triply periodic minimal surface based porous media

With the fast development in the field of additive manufacturing, triply periodic minimal surface (TPMS) based porous media have recently found many uses in mechanical property tuning. However, there is still a lack of understanding in their porosity-dependent perme-ability and electrical as well as thermal conductivity. Here, we perform finite volume sim-ulations on the solid and void domains of the Schoen gyroid (SG), Schwarz primitive (SP) and Schwarz primitive beam (SPB) TPMS with porosities between 63% and 88% in Ansys Fluent. A simple cubic lattice (CL) of equivalent porosity served as reference. The SPB and CL showed up to one order of magnitude higher permeabilities than the SG and SP. However, SG and SP have about 1.3 and 2.6 times the electrical and thermal conductivity of SPB and CL, respec-tively. Furthermore, the properties of SPB and CL are largely affected by the surface area density, whereas tortuosity variation does not impact permeability and conductivity to a major extent. Finally, empirical relations are adapted to describe the presented data and thus, they may enable future designers of TPMS based porous structures to fine-tune the geometries according to the requirements on permeability and electrical as well as thermal conductivity.(c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

This study used finite volume simulations to investigate the effect of porosity on the permeability and electrical as well as thermal conductivity of TPMS porous media. The results revealed significant differences in performance among different TPMS structures, with SPB and CL exhibiting higher permeabilities while SG and SP having higher electrical and thermal conductivity. Surface area density was found to significantly impact the properties of SPB and CL, while tortuosity variation had a minor effect on permeability and conductivity.