Numerical advective flux in highly variable velocity fields exemplified by saltwater intrusion

摘要

Numerical simulation of advective solute transport requires approximation of two vectors: the concentration gradient and the velocity. Estimation of the concentration gradient by Eulerian solution techniques gives rise to classical 'numerical dispersion' since the truncation error is of the formΔ~2C. Truncation of the velocity vector has escaped close scrutiny because the velocity field generally varies slowly in space in most groundwater environments. However, in many problems, including saltwater intrusion, the velocity field is highly variable and error associated with velocity approximation strongly affects the solution.