摘要
对对流占优的三维溶质运移问题提出了分步广义迎风解法，首先利用Ｎ．Ｎ．Ｙａ－ｎｅｎｋｏ对水动力弥散方程分步求解的思想，将原来的一个定解问题分解为两个定解问题即对流定解问题和扩散定解问题，对对流定解问题采用广义迎风对偶单元均衡法求解，对扩散定解问题采用一般的Ｇａｌｅｒｋｉｎ有限元法求解，不仅避免了用一般有限元法和有限差分法求解对流占优的地下水水质数学模型时常出现数值弥散和过量问题，而且避免了求节点速度这一步，节省运算步骤，对井点的浓度变化给出了更合适的求解方法。
A generalized upwind scheme with fractional steps for 3 D mathematical models of convection dominating groundwater quality is suggested. The mass transport equation is changed into a convection equation and a dispersive equation. The generalized upwind scheme is used to solve the convection equation and the finite element method is used to compute the dispersive equation. These procedures, which not only overcome the phenomenon of the negative concentration and numerical dispersion appearing frequently when using normal FEM or FDM to solve models of convection dominating groundwater transport, but also avoid the step for computing each node velocity to give a more suitable method to calculate the concentrations of the well points.
关键词
溶质运移问题
对流占优
广义迎风解法
地下水
three dimensional problem of groundwater transport, convection dominating, fractional steps, generalized upwind scheme
