H. Ted Davis1, Daniel Kroll2, Robert Maier3, R. S. Bernard4, S. E. Howington4, and John F. Peters5. (1) University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455, (2) University of North Dakota, Fargo, ND 58108, (3) U.S. Army Engineer Research and Development Cente, Vicksburg, MS 39180-6199, (4) Coastal and Hydraulics Laboratory Waterways Experiment Station, U.S. Army Corp of Engineers, Vicksburg, MS 39180-6199, (5) Geotechnical Laboratory, Waterways Experiment Station, U.S. Army Corp of Engineers, Vicksburg, MS 39180-6199
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.