© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim An investigation is presented into modeling of gas flow through particle/fiber hybrid composite materials designed for use as diesel particulate filters (DPFs). The work leads to the creation of a modified version of the Carman–Kozeny equation, specifically tailored for such structures. Details of computational fluid dynamics (CFD) simulation of gas flow through modeled structures are provided, leading to formulations to account for the loss of surface area associated with sintering and a tortuosity effect dependent on the porosity level. Based on these outcomes, a simple analytical expression is derived, and it is shown that predicted permeability values obtained with it are in good agreement with experimental data.