Calibration of one-dimensional flow setup used for estimating fabric permeability using three different reference media

摘要

Experimental estimation of the permeability of reinforcement fabrics is very important in conducting accurate mold-filling simulations for liquid composite molding (LCM) processes employed to manufacture polymer matrix composites. In this study, the one-dimensional (1D) flow based permeability measuring setup was calibrated for the first time using three different reference media: an aluminum block with drilled parallel holes, a lattice of 3D unit cells created using rapid prototyping, and carbon fabric used in the recently concluded permeability bench-mark study [Vernet N, et al. Compos Part A, 61, 172 (2014)]. The steady-state permeability was estimated for all the three cases while the transient permeability was estimated only for the lattice-type and carbon fabric media. The carbon-fabric results were presented as the transient and steady-state permeabilities for three different directions of 0 degrees, 45 degrees, and 90 degrees, and the in-plane principal permeability components were calculated using the correlations for anisotropic fabrics. The results for the aluminum-plate and lattice-like media were compared with the previous numerical and experimental studies and good agreement was observed. To validating the carbon-fabric results, the experimental permeability was compared with two different analytical permeabilities for dual-scale porous media [Papathanasiou, Int. J. Multiphase Flow, 27(8), 1451 (2001) and K.M. Pillai and S.G. Advani, Transport Porous Med., 21(1), 1 (1995)], and a good agreement with experimental results established the accuracy of our 1D flow setup. The study raises some important questions on the permeability benchmark study conducted recently [Vernet N, et al. Compos Part A, 61, 172 (2014)]. POLYM. COMPOS., 37:925-935, 2016. (c) 2014 Society of Plastics Engineers