Morphology, flow and heat transfer in triply periodic minimal surface based porous structures

Abstract Porous structures are ubiquitous in many thermal management and energy conversion systems. The morphology of a porous structure has significant impact on the fluid flow, heat/mass transport, and strength performance. However, the available fabrication techniques are not capable of directly tailoring porous structures with well-controlled pore features and functional graded pore morphology, thereby limiting the performance enhancements for these systems. In this study, a triply periodic minimal surface (TPMS) based method was developed to customize the morphology of porous media with well-controlled pore features and to fabricate these parts with additive manufacturing. Porous structures with designed pore parameters were built based on the mathematically defined iWP surface, primitive surface, diamond surface and gyroid surface. Before performing flow and heat transfer simulations, morphological analysis was conducted to establish the connections between the geometrical parameters and the performance of the porous structure (flow resistance, heat transfer, and strength). The porous structures were compared in terms of their structural strength, specific pressure drop, interstitial/volumetric heat transfer coefficients and the ratio of the Colburn factor relative to the friction factor. The TPMS porous structures indicated that much higher strength than the simple cubic packing structure (approximation of sintered metal particles) due to their reasonable struct connectivity. Computations demonstrated that the type P structure had the lowest flow resistance and highest comprehensive heat transfer coefficient (j/f). The high specific surface area, continuous changes in the flow direction, periodic mixing/redistribution and flow acceleration contributed to the higher volumetric heat transfer coefficients in the type W/G structures.