Reliable flow simulation software is inevitable to determine an optimal injection strategy in Liquid Composite Moulding processes. Void formation during the injection phase can be explained as a consequence of the non-uniformity of the flow front progression. Origin of this fact lies in the dual porosity of the fibre preform and therefore the best explanation can be provided by mesolevel analysis. In the mesolevel analysis, single scale porous media (fibre tows) and open spaces are presented in the flow domain and therefore different flow regimes must be considered and linked together in one analysis, at each time step. In such simulation it is extremely important to account correctly for the surface tension effects, which can be modelled as capillary pressure applied at the free flow front, [
Post-processing a finite element solution is a well-known technique, which consists in a recalculation of the originally obtained quantities such that the rate of convergence increases without the need for expensive remeshing techniques [
]. Post-processing is especially effective in problems where better accuracy is required for derivatives of nodal variables in regions where Dirichlet essential boundary condition is imposed strongly [
]. Consequently such an approach can be exceptionally good in modelling of resin infiltration under quasi steady-state assumption, because only free-front normal velocities are necessary to advance the resin front to the next position.
The new contribution lies in the post-processing free-boundary velocities implementation in the mesolevel infiltration analysis. Such implementation ensures better accuracy on even coarser meshes, which in consequence reduces the computational time also by the possibility of employing larger time steps. Suitability of the known technique is analysed for Darcy’s flow, new procedure is suggested for Stokes’ flow, a methodology for regions with different permeabilities is introduced and conclusions are taken.