Computing Pore Size Distribution in Non-woven Fibrous Filter Media

Fundamental understanding of transport properties of non-woven fibrous material is depended on in dept cognition of their microstructure. Non-woven fibrous filter media are formed by the random distribution of fibers in a specific space exhibit a complicated pore size structure. Computing pore size distribution (PSD) is a vital parameter in studying material transport dynamics. In this work, a theoretical model was suggested based on the gamma distribution and fiber orientation distribution to predict the PSD in non-woven fibrous filter media. In parallel, the analytical model was compared with the previous PSD theories and experimental results. The 3D virtual fiber structure was constructed by using GeoDict code, and the pore size was represented by the inscribed circle diameter. Parameters influencing the PSD were studied, including fiber diameter, porosity, and fiber orientation. Comparison of simulation results with analytical model was made. The results demonstrate that the angle between the fiber and the Z-axis has little effect on the PSD. When the porosity is consistent, smaller pores can be formed by reducing fiber diameter. With the fiber diameter is constant, larger pores can be formed by increasing the porosity.