Eulerian-Lagrangian methods for advection-dispersion.

Three different Eulerian-Lagrangian schemes are used to solve the one-dimensional advection/dispersion equation. Advection is formally decoupled from dispersion, and the resulting advection problem is solved by a novel approach called the method of revere streaklines, and by the more conventional method of continuous particle tracking. Dispersion is handled by implicit finite elements on a fixed grid, using linear and quadratic basis functions. The results are compared with a third Eulerian-Langrangian method in which the concentration function remains undecomposed. Preliminary results suggest that the first two methods may, after further improvement, work well for a wide range of Peclet numbers. (from authors' abstract)