地下水中污染物运移过程数值模拟算法的比较

Numerical methods comparison in simulating contaminants movement in groundwater

数值模拟已成为目前地下水有机污染现场中,预测和评价溶解相有机污染物运移的主要手段。自从MT3D问世以来,它在地下水溶质运移的模拟中得到了广泛的应用。MT3D中包含有4种不同的数值算法——MOC,MMOC,HMOC和UFDM。利用Processing MODFLOW Pro.7.0.5建立了均质一维流动的地下水数学模型,考虑溶解相有机污染物在地下水中运移时的4个主要影响因素——对流、弥散、吸附和降解,设定了14种代表性的情形,模拟了等浓度污染源条件下污染物的运移,并将不同数值算法的计算结果与理论解进行比较,从而研究不同数值算法的优缺点,为实际数值模拟时算法的选择提供依据。

Numerical simulation technology has been playing an important role in groundwater researches. After the development of MT3D, it has been widely used to predict and evaluate the fate and transport of the dissolved contaminants in groundwater. MT3D has four different numerical solvers in it-MOC, HMOC, MMOC and UFDM. In order to research the applicability of these four different numerical methods, a one dimensional numerical groundwater flow model was developed via Processing MODFLOW Pro. 7. 0. 5, 14 cases, combined by different dispersivities, adsorption coefficients and degradation rates, were simulated, and the results were compared with the theoretical results. Suggestions on how to select the numerical solvers for different simulating needs are summarized based on this research.