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An experimental technique is described which can be used to measure simultaneously the three principal permeabilities of fiber reforms made of continuous or short fibers. The technique utilizes embedded optical fibers for detecting the position of the liquid front inside the reform. Expressions were derived for calculating the permeabilities from the three-dimensional measurement of the liquid front. Permeabilities measured by the present fiber optic and by the conventional, pressure drop and flow visualization techniques were compared. Good agreements were found between the results of these techniques.

A model is presented of the steps involved in the manufacturing process of semicrystal line thermoplastic matrix composites. The model relates the temperature and pressure ap plied during processing to a) the flow of the matrix into the fiber tow, b) the formation of contact and bond between adjacent plies, and c) the crystallinity. The results of the model were verified by tests performed with PEEK 150P polymer and APC-2 graphite/PEEK composite.

SUMMARYNumerical simulation of uid ow with moving free surface has been performed. For the free surface ow, a volume of uid (VOF)-based algorithm utilizing a ÿxed grid system has been investigated. In order to reduce numerical smearing at the free surface represented on a ÿxed grid system, a new free surface-tracking algorithm based on the donor-acceptor scheme has been proposed. Novel features of the proposed algorithm are characterized by two numerical tools; the orientation vector to represent the free surface orientation in each cell and the baby-cell to determine the uid volume ux at each cell boundary. The proposed algorithm can be easily implemented in any irregular non-uniform grid systems usually encountered in the ÿnite element method (FEM). Moreover, the proposed algorithm can be extended and applied to the 3D free surface ow problems without additional e orts. For computation of unsteady incompressible ow, a ÿnite element approximation based on the explicit fractional step method has been adopted. In addition, the streamline upwind=Petrov-Galerkin (SUPG) method has been implemented to deal with convection dominated ows. Combination of the proposed free surfacetracking scheme and the explicit fractional step formulation resulted in an e cient solution algorithm. Validity of the present solution algorithm was demonstrated from its application to the broken dam and the solitary wave propagation problems.