Lattice Boltzmann simulation of dissolution and precipitation in porous media

Abstract

In this paper, we simulate numerically the dissolution and precipitation in porous media by using the lattice Boltzmann method (LBM). The fluid flow in porous media is simulated by using a multiple-relaxation-time (MRT) LBM, while a D2Q9 lattice BGK model is used for reactive solute transport. Frst, the code of LBM is tested by simulating the diffusion and reaction at a boundary in an open rectangular domain, and comparing the results with the analytic solution. Then, the effects of the Reynolds number (Re), the Schmidt number (Sc) and the Damkohler number (Da) on the variations of the geometry of the porous media and the concentration field are carefully studied. It can be found that for the dissolution (precipitation), as Re is increased, the porosity of the porous media will be increased (decreased), and the average concentration will be decreased (increased). Besides, at low Damkohler numbers or Schmidt numbers, the dissolution and precipitation will be reaction-controlled and are highly uniform. However, as Da or Sc is high, the dissolution and precipitation will be diffution-controlled, and mainly occur in the upstream and large pore space.