Modeling void formation dynamics in fibrous porous media with the lattice Boltzmann method

A novel technique for simulating multicomponent fluid flow in the microstructure of a fiber preform is developed, which has the capability of capturing the dynamics of void formation. The model is based on the lattice Boltzmann (LB) method, a relatively new numerical technique which has rapidly emerged as a powerful tool for simulating multicomponent fluid mechanics. The primary benefit of the lattice Boltzmann method is the ability to robustly model the interface between two immiscible fluids without the need for a complex interface tracking algorithm. In a previous paper (Spaid, M.A.A. and Phelan F.R., Jr, Lattice Boltzmann methods for modeling microscale flow in fibrous porous media, Physics of Fluids, 1997, 9(9), 2468), it was demonstrated that the lattice Boltzmann method may be modified to solve the Stokes/Brinkman formulation for flow in heterogeneous porous media. Multicomponent infiltration of the fiber microstructure is modeled by combining the Stokes/Brinkman LB method, with the multicomponent LB algorithm described by X. Shan and H. Chen (Lattice Boltzmann model for simulating flows with multiple phases and components, Physics Review E, 1993, 47, 1815). Numerical results are presented which compare void formation dynamics as a function of the nominal porosity for a model fiber microstructure. In addition, unsaturated permeabilities obtained from the numerical simulations are compared with saturated results for flow in the model porous microstructure.