The impeller-wise circulation flow C was divided according to the number of flow loops as in references , and the exchange flows E according to the number of compartments perpendicular to the flow . The turbulent exchange flows were furthermore multiplied by the number of compartments parallel to the flow to complete the finite-volume discretization of the diffusive exchanges. The impeller-wise tangential circulation flow was assumed to be equal to the impeller's main circulation flow C , but it was divided according to the number of flow loops in the tangential direction. The compartment volumes were kept equal within the flow loops . Twelve tangential compartments were used in each tank and the number of flow loops ranged from 8 to 15, which yielded in total from 10 000 to 25 000 compartments per tank. The circulation and exchange flow numbers, C and E , were fitted to reproduce the local mixing times and tracer curves reported in literature.