Analysis of Airflow Through a Porous Gas Mask Filter Cartridge

Abstract

Gas mask filter cartridges are essential protective devices that prevent the inhalation of hazardous gases and airborne contaminants while maintaining acceptable breathing comfort, where airflow behaviour through the porous filter material strongly influences pressure drop and breathing resistance. The aim of this study is to analyse airflow characteristics through a porous gas mask filter cartridge using Computational Fluid Dynamics (CFD) to evaluate the effects of inlet velocity and filter thickness on airflow performance. A three-dimensional model of the filter cartridge was developed and simulated using ANSYS Fluent under steady, incompressible, and isothermal conditions. The porous filter was modelled using a homogeneous porous media approach with a porosity of 0.8. Three inlet velocities of 1.0 m/s, 1.5 m/s, and 2.0 m/s were applied to represent different breathing intensities, while three filter thicknesses of 28 mm, 30 mm, and 32 mm were investigated. The results show that increasing filter thickness leads to higher flow resistance, causing greater pressure drops and reduced airflow velocity within the porous region. Quantitatively, a pressure drop of approximately 279 Pa was obtained at an inlet velocity of 1.0 m/s, with pressure losses increasing consistently as inlet velocity and filter thickness increased. The 32 mm filter produced the highest pressure drop and lowest airflow velocity, whereas the 28 mm filter showed the lowest resistance but may compromise filtration effectiveness. Overall, the 30 mm medium-thickness filter provided the most balanced performance by maintaining acceptable airflow while avoiding excessive pressure loss. These findings demonstrate that CFD is an effective tool for evaluating airflow behaviour and supporting the optimisation of gas mask filter cartridge design.