Simulation Software for Flow of Fluid with Suspended Point Particles in Complex Domains: Application to Matrix Diffusion

Matrix diffusion is a phenomenon in which tracer particles convected along a flow channel can diffuse into porous walls of the channel, and it causes a delay and broadening of the breakthrough curve of a tracer pulse. Analytical and numerical methods exist for modeling matrix diffusion, but there are still some features of this phenomenon, which are difficult to address using traditional approaches. To this end we propose to use the lattice-Boltzmann method with point-like tracer particles. These particles move in a continuous space, are advected by the flow, and there is a stochastic force causing them to diffuse. This approach can be extended to include particle-particle and particle-wall interactions of the tracer. Numerical results that can also be considered as validation of the LBM approach, are reported. As the reference we use recently-derived analytical solutions for the breakthrough curve of the tracer.