Suitability of Numerical Simulation for Two Computations of Longitudinal Dispersivity in Heterogeneous Media

By establishing representative heterogeneous model and simulating, this paper analyzed the exactitude and suitability of two commonly used methods to compute longitudinal dispersivity in the numerical simulation for different conditions, including the dispersive-area (DA) method and the linear-graphic(LG)method. The results indicated that in the research both methods could get good values of longitudinal dispersivity caused by heterogeneity and could be suitable for different contaminated source concentrations and heterogeneity in the numerical simulation. But for different hydraulic gradients and grid sizes in the numerical simulation, LG method was more suitable. The changes of longitudinal dispersivity with the grid sizes were mainly caused by numerical dispersion.