Modeling and CFD-simulation of woven textiles to determine permeability and retention properties

The previous paper (No. 2, Vol. 12-2011) [1] were analyzed the weave and construction parameters of high density woven fabric and their influence on the pore morphology, which directly effects the functional properties such as permeability and retention. The analysis encompassed physical and optical methods of testing. In this paper, newly developed methods, tools and programs will be presented for virtual imaging of the multi-filament woven fabric geometry with pore structure used to determine permeability and retention properties. Two methods are applied for the generation of virtual fabric. One method involves developing software that is able to model woven fabric in new condition from a series of realistic input parameters. In this step, deterministic and stochastic methods are combined to create the fabric’s geometry. The other method involves reconstruction/generation the 3D woven geometry from sequences of 2D cross section images. The results prove that the 3D pore morphology of high density multi-filament fabric can be illustrated in correlation of the woven construction parameters. The developed methods for modeling and the CFD simulation of woven fabric build an important basis for determining the mechanical flow properties such as permeability and retention characteristics of filters and barrier textiles. Additionally, the effects of mechanical loads on the fabric morphology and on the permeability values will be analyzed by applying uniaxial and biaxial tensile loads to the fabric. The tests provide the basis for a realistic prediction to the effects of the machine and construction parameters on the fabric properties and the resulting permeability and retention. These predictions can aid in analyzing the suitability of a fabric for a specific application.