The growing demand for high-performance thermal management in aerospace and electronics systems has renewed interest in passive two-phase heat transport devices such as heat pipes. The design of the porous wick structure is a critical factor governing heat pipe performance, as it controls both capillary pumping and conductive heat transfer. Triply periodic minimal surface (TPMS) structures have recently emerged as promising wick candidates owing to their tunable topology, high surface-area-to-volume ratio, and compatibility with advanced manufacturing techniques. However, validated numerical methodologies for the estimation of their effective hydraulic properties remain limited in the literature. In this work, a multiscale modeling framework is developed to characterize the hydraulic permeability and effective pore radius of three TPMS topologies—Diamond, Gyroid, and Primitive—over a range of unit-cell sizes and porosities.