Abstract. Methods are presented for calculating the geometric parameters of evolving porous media in composite materials (CMs) produced via various gas-phase technologies with common multi-directional and randomly reinforced structures. An analytical calculation of porous media geometric parameters was performed for both multi-directional (2D, 3D, 4D, and 5D) structures, consisting of continuous fiber elements idealized as straight cylindrical rods (or fiber bundles) with circular cross-sections, and randomly reinforced composites based on discrete fiber fillers. The random structure of such porous media is approximated as a regular structure formed by a system of cylindrical rods. Models of porous preforms (aligned and randomly reinforced) and corresponding composites are proposed, alongside methods for describing the CM structure during the simulation of gas-phase infiltration of fibrous preforms for carbon-carbon and ceramic-matrix materials. Key parameters of the evolving porous media were determined, including initial, instantaneous [current], and ultimate values for porosity, specific surface area, and reinforcing fiber radii. The proposed calculation methods serve as structural description elements for developing software to simulate isothermal and thermal-gradient chemical vapor infiltration of fibrous preforms to produce carbon-carbon and ceramic-matrix composites with minimal or specified porosity. This methodology is applicable as a computational component for modeling and determining the thermal conductivity of the considered structures. Furthermore, the initial porosity calculations can be used to optimize the liquid-phase infiltration of porous preforms in the manufacturing of CM components. 

Keywords: multi-directional composite material, randomly reinforced composite material, porous media modeling

For citation: Nilov A. S., Butorina I. A., Mokhova E. A. Computational determination of evolving porous media parameters for multi-directional and randomly reinforced composite structures. Aerospace Engineering and Technology. 2026. Vol. 4, no. 2, pp. 250–263. (In Russ.) https://doi.org/10.52467/2949-401X-2026-4-2-250-263; https://elibrary.ru/hqgnms

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