Semi-empirical equation for determining the pressure drop of nanofibers

Air pollution, particularly the presence of particulate matter, has been linked to increased mortality rates. Air filtration is a widely used method to reduce exposure to airborne particles and protect public health. Nanofiber filter media has gained attention due to its ability to efficiently remove nanosized particles while minimizing pressure drop. However, accurately predicting the pressure drop in nanofiber media, which is influenced by the slip flow effect, remains a challenge. In this study, a simple semi-empirical equation was developed to calculate the pressure drop across nanofiber filter media. The model considers various filter parameters such as diameter, thickness, and solidity. Existing theoretical and empirical models were compared with experimental data, revealing limitations in accurately predicting pressure drop in nanofibers. To address this, a new empirical model, proposed by Bian, was examined. However, the Bian model demonstrated limited applicability due to its specific range of solidities. Numerical simulations were conducted to obtain additional pressure drop data, and a total of 107 cases were tested across various filter parameters. The simulations were performed using the Stokes equation to account for the low Reynolds numbers associated with nanofibers. The developed semi-empirical model provides a practical tool for analyzing the effect of filter parameters on nanofiber filter media's pressure drop, aiding in the design of efficient air filtration systems.