Numerical modeling of the air permeability of two-layer woven structure ensembles

Abstract

This study aims at investigating air permeability in the transversal direction of pairs of woven textiles. Three samples of woven macrostructures with different characteristics are selected for the numerical investigation of 16 two-layer ensembles. Computational fluid dynamics (Reynolds-averaged Navier–Stokes equations) is used for modeling the air permeability, applying the theory of jet-systems: the flow through each of the layers in the ensemble is modeled as an “in-corridor” ordered jet-system. The influence of the order of arrangement of the layers in the ensemble is analyzed, indicating higher air permeability of the ensemble when a tighter structure is placed as a first layer. The effect of the distance between the two woven macrostructures is also analyzed, showing a strong influence on the flow development as well as on the extrema of flow velocities, especially in the drop of the flow velocity in the air gap between the two layers. The analysis made and the results obtained show that the method can be applied for further investigation of ensembles of textile layers.