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

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°, 45°, and 90°, 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. © 2014 Society of Plastics Engineers