(78b) "Wall Enhanced Dispersion in Cylindrical Packed Beds,"

In pore-scale simulations of flow in cylindrical bead packs, we found that the effective longitudinal dispersion coefficient increases with increasing radius of the cylinder. The implication is that all longitudinal dispersion coefficients reported from measurements in tubes depend on the effective radius of the tubes. A generalization of the Taylor-Aris model of dispersion in a tube provides qualitative predictions agreeing with the simulation results.