Wicking across a Fiber-Bank

This paper presents an experimental study of the capillary-driven flow of viscous liquids across a bank of aligned fibers. The dimensions of the flow domain are of the same order as that of fiber tows in a woven fiber mat. In this paper, an expression based upon energy balance principle is proposed for the capillary suction pressure and is compared with the other expressions. The efficacy of different permeability models for flow inside the fiber bundle is also tested. A model for the absorption of the liquid based on Darcy's Law along with Washburn's equation is compared with the results from the experiments for five different liquids at fiber volume fractions from 0.4 to 0.8. The effect of fiber volume fraction and the material properties of the fluid–fiber system upon the rate of wicking of fluid across the fiber-bank is studied. Comparison of across the fiber wicking flow with that along the fibers is also done.