Crank–Nicolson–Galerkin model for transport in groundwater: Refined criteria for accuracy

摘要

The Crank–Nicolson–Galerkin model (CNGFEM) is reported to be accurate in predicting advective–dispersive transport when the product of the mesh Peclet number (Pe) and the Courant number (Cr) is less than, or, equal to 2. However, numerical experimentation involving the application of the CNGFEM to simulate contaminant transport in groundwater has shown that the model prediction can be oscillatory for some values of the Peclet number. Furthermore, the accuracy of prediction has also been found to be a function of the source definition. The objective of this paper has been to develop refined criteria for the CNGFEM to provide oscillation-free accurate results for contaminant transport in groundwater from different types of sources. The refined criteria require that Pe⩽50, PeCr⩽5, and Cr⩽1 for continuous sources. And for pulse sources, oscillation-free accurate results are obtained when Pe⩽20, PeCr⩽5, and Cr⩽1.