Maximizing the transport properties of two-dimensional fibrous materials

Fibrous materials show inferior anisotropic properties and inadequate performance due to their non-optimized microstructures despite the tremendous advances evolved in the manufacturing of customized geometries. The present work provides the optimized microstructures of fibrous materials to maximize their transport properties. By presenting easy-to-use closed-form formulae, the study further reveals the realistic functionality of the inplane and through-plane transport properties of two-dimensional fibrous media with the key parameters namely fiber diameter, fiber spacing and fiber angle at a non-varying porosity. The results show that equal fiber spacings in different layers enhance all the through-plane and in-plane bulk properties. However, the optimal fiber spacings that maximize or minimize a bulk property in the in-plane direction of interest can vary depending on the other parameters including porosity. It is also found that for high heat transfer and low pressure drop applications, the minimum and maximum fiber diameters are respectively required. The orthogonal arrangement of fibers with equal spacings results in the maximum through-plane conductivity and heat transfer coefficient. The provided Excel spreadsheet calculators can be readily used for predicting and optimizing the conductivity, permeability, pressure drop and Nusselt number of two-dimensional fibrous materials in the in-plane and through-plane directions.