The objective of this work is to propose a procedure to simulate the flow in the LCM (Liquid Composites Molding) processes by finite difference discretization in a curvilinear coordinate system adapted to the shape of the saturated zone. The numerical results obtained are compared with experimental results obtained by an experimental device elaborated at our laboratory. It allows to realize linear and radial injections for different porosities and to observe the flow front kinetics. Numerical and experimental results are then compared with those of the literatures and excellent agreements are noticed. Finally, we suggest a concept of the capillary number to explain the variations of the permeability obtained for pressure values lower than 0.25 Bar.