OPTIMIZATION OF THE FRACTAL-LIKE ARCHITECTURE OF POROUS FIBROUS MATERIALS RELATED TO PERMEABILITY, DIFFUSIVITY AND THERMAL CONDUCTIVITY

Abstract

In this study, the optimization of the fractal-like architecture of porous fibrous materials related to permeability, diffusivity, and thermal conductivity was analyzed by applying the established theoretical models. It was observed that the ratio of dimensionless permeability over dimensionless effective diffusivity decreased with the decrease of porosity and tortuosity fractal dimension, respectively, which implied that lower porosity and tortuosity fractal dimension were beneficial to wind/water resistant fabric, as it reduced the ratio of dimensionless permeability over dimensionless effective diffusivity. Besides, it was found that the ratio of the dimensionless total effective thermal conductivity over dimensionless effective diffusivity increased with tortuosity fractal dimension, which implied lower tortuosity fractal dimension was beneficial to clothing insulation, as it reduced the ratio of dimensionless total effective thermal conductivity over dimensionless effective diffusivity. The optimization results indicated that fabrics with more aligned fibers were preferred for protective clothing, as the low tortuosity fractal dimension implied fibers in the fibrous materials should be more aligned.