Fractal approach to structure and thermal property of down fiber assembly

Down fiber assembly is a heterogeneous and hierarchical system whose structure can be hardly characterized. At the meantime, its thermal property is valuable for usage, it would guide design if the correlation between thermal performance and structure can be understood. In this paper, fractal approach was introduced to characterize the microstructure of down fiber assembly. Fractal dimensions of fiber assemblies are calculated by box-counting method and are found to be positively correlated with basic structural parameters such as fiber mass and volume fraction. Meanwhile, the results indicate that increasing fractal dimension will lead to an enhancement of thermal insulation performance.