Entropy generation-based computational geometry optimization of the pore structure of high-conductivity graphite foams for use in enhanced heat transfer devices

• An optimal pore-level geometry for high-conductivity graphitic foams is sought.
• The criterion of entropy generation minimization is employed.
• Operating conditions relevant to enhanced heat transfer are considered.
• Constraints imposed to ensure a realizable geometry.
• Elongated ellipsoidal geometry significantly reduces convective thermal resistance.

A computational fluid dynamics-based shape optimization process is employed to determine a pore-level geometry for high-conductivity graphitic foams which is optimal with respect to the criterion of entropy generation minimization, under operating conditions relevant to the implementation of such a foam in an enhanced heat transfer device. The optimization procedure is applied to a single pore, subject to operating conditions which reflect a typical pore in the bulk of the foam, far removed from the influences of the macroscopic boundaries of the porous region. Constraints are imposed upon the geometry to ensure the pore structure arrived at may be manufactured by a reasonable process, and to ensure the validity of the analysis. The optimal, ellipsoidal pore geometry obtained is found to achieve a significant reduction in the resistance to convective thermal exchange between constituents, at the cost of an increased resistance to fluid flow.