The ability to precisely predict the permeability of woven fabrics is compulsory to simulate the RTM processes without having to realize time consuming experiments for each new fabric. Channel network models are generally not working very well with laminates of woven fabrics because of the nesting between the plies that creates a highly complex network. Thus, 3D meshes of woven fabric unit cells are realized via a defined number of steps to resolve Stokes and Brinkman equations on a periodical elementary cell using a 3D FE code. Shearing and compression are the most important deformation modes and the determination of their respective influence on the permeability tensors is of prime importance. Therefore, a comparison between WiseTex and Hivet's models of sheared and copressed fabrics is presented. Finally, the representativeness of the elementary volume is discussed in the case of an idealised UD fabric.