H. Ted Davis1, Daniel M. Kroll2, Robert S. Maier3, R. S. Bernard4, S. E. Howington4, and John F. Peters5. (1) University of Minnesota, 421 Washington Ave SE, Minneapolis, MN 55455, (2) Department of Physics, University of North Dakota, South Engineering 216, Fargo, ND 58108, (3) Coastal and Hydraulics Laborator Waterways Experiment Station, U.S. Army Corp of Engineers, 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.