Date of download: 12/31/2017 Copyright © ASME. All rights reserved. From: Three-Dimensional Computational Modeling of Subject-Specific Cerebrospinal Fluid Flow in the Subarachnoid Space J Biomech Eng. 2008;131(2):021010-021010-11. doi:10.1115/1.3005171 Figure Legend: Porous media representation of the SAS, (a) Representative porous model for CFD, (b) Representative unit cell and permeability directions, (c) permeability variation with porosity (The number of “RUCs” across a channel can be more than one)