Mixing at fracture intersections: Influence of channel geometry and the Reynolds and Peclet Numbers

The 3D lattice Boltzmann (LB) method was used to model mixing at three types of continuous fracture intersections: planar, fluted (containing parallel grooves), and rough‐walled. Peclet number ( Pe ) varied from 3 to 400, and Reynolds number ( Re ) varied from 0.5 to 100. In both planar‐ and rough‐walled intersections, the mixing ratio ( M r ) decreases with increasing Pe , though the decrease is less dramatic for the rough‐walled geometry. In planar‐walled intersections, the M r decreases with increasing Re ; however, the fluted and rough‐walled intersections show the opposite trend. Overall, the impact of inertial effects is slight for Re ≤ 10. The effects of channel length are also small; the calculated M r varies little for LB simulations with length/width ≥ 1.