A method of making a fibrous part is provided. The method may comprise forming a porous structure with an annular geometry. A first entrance channel and a second entrance channel may be formed with the entrance channels defined by a surface of the preform. The entrance channels may also extend in a radial direction from an inner diameter of the annular porous structure partially across the surface. An exit channel may be formed between the entrance channels and defined by the surface. The exit channel may extend in a radial direction from an outer diameter of the annular porous structure partially across the surface.