Parametric Numerical Investigation of Argon Transport in TPMS Porous Structures: Permeability and Outlet-Flow Uniformity

Triply periodic minimal surface (TPMS) structures offer smooth, interconnected flow channels and are promising as additively manufactured flow-equalizing inserts for local inert-gas delivery systems. This study used pore-resolved simulations to analyze argon transport through Diamond (D), Gyroid (G), and Primitive (P) TPMS architectures. Equivalent flow resistance was assessed via pressure drop-based permeability metrics, and outlet-flow uniformity was measured with a velocity uniformity index. The impacts of porosity, unit-cell size, wall thickness, and topology were examined, recognizing their coupled nature. Higher porosity enhances gas throughput but slightly improves outlet uniformity. Larger unit cells significantly lower hydraulic resistance and boost permeability but tend to create preferred flow paths, reducing uniformity. Thicker walls decrease effective flow area and increase viscous resistance. Among the configurations studied, G-type topology offers the best balance between gas throughput and outlet-flow uniformity. Based on permeability and uniformity rankings, G-type structures with high porosity and medium-to-large unit cells are promising for future device evaluations. This work is an idealized, single-component numerical study, without considering external Ar-air mixing, oxygen levels, thermal effects, manufacturing variations, or experimental validation. Therefore, the identified parameter space should be viewed as a hydrodynamic screening outcome rather than a definitive engineering design for shielding performance.