In-Plane Flow of Fluids in Fabrics: Structure/Flow Characterization

A technique that quantifies the in-plane flow properties of fibrous networks is pre sented. A radial flow geometry allows the simultaneous study of more than one in- plane flow direction. The shape and position of a radially advancing fluid front define directional permeabilities in the plane, which can be used to compare structurally different fibrous networks. Confirmatory studies reinforce the method of data analysis and show that the directional permeabilities are independent of driving pressure, fluid viscosity, and fiber surface wettability properties. The methodology was applied to the study of multilayer assemblies. The in-plane flow of fluids in heterogeneous multilayer constructions is governed by the high permeability layer. A transverse flow mechanism is proposed as being responsible for filling the low permeability layers and, therefore, the transverse permeability is coupled into this flow process.