Multi relaxation time lattice Boltzmann simulations of multiple component fluid flows in porous media

The flow of fluid mixtures in complex geometries is of practical interest in many fields, ranging from oil recovery to freeze-dried food products. Due to its inherent locality the lattice Boltzmann method allows for straightforward implementation of complex boundaries and excellently scaling parallel computations. The widely applied Bhatnagar Gross Krook (BGK) scheme, used to model the contribution of particle collisions to the velocity field, does however suffer from limitiations in precision that become more prominent with increasing surface to volume ratio. To increase the accuracy of simulations of mixtures in porous media, we integrated a so-called multi relaxation time (MRT) collision scheme with a pseudo-potential method for fluids with multiple components. We describe some optimisation details of the implementation and present test results verifying the physical accuracy as well as benchmarks obtained on the XC2 Opteron cluster at the Scientific Supercomputing Centre Karlsruhe (SSCK)