含裂隙含水层污染物生物降解数值方法

本文讨论了含裂隙介质地下水污染物输运与生物降解非线性方程组数值求解方法.方程含有对流项、扩散项、生长、死亡、吸附、解吸、趋化和孔隙与裂隙介质界面间的交换项的非线性偶合，使算法十分困难.本文讨论了无生化过程时的几种求解方法，数值结果表明：用三次迎风插值法对常见的对流项占优势，且场变量有较大梯度的问题较适用.在讨论有生化反应过程时，利用对流项与生化反应项的特征时间量级估算，给出了求生化过程作用子步的时间步长估算办法.用上述方法所得到的模拟结果与解析解、无化学反应和有化学反应的实测值对比，吻合很好

The study of a numerical method about biodegradation of contaminants in the fractured media

In this paper a numerical method for equations of transport and biodegradation in the fractured media is discussed.Because the equations consist of terms related to advection,diffusion,biochemical as well as the term of exchange betwen the fracture and the porous media,it is very difficult to find their solution.In order to find more efficient method for solving these equations,several numerical methods for the equations without biochemical terms are discussed first.The numerical results show that the cubic spline method can be used to solve advection flow dominated problem which often occurred in the fractured media.Then,the equation with both advection-diffusion term and biochemical term are discussed.The splitting-operator is used to decouple the advection and diffusion terms with biochemical term in the equations.The way to determine the smaller time step for solving fast biochemical terms is introduced through comparing the order of characteristic time of biochemical term with that advection(diffusion)term.Numerical simulation results show that good agreement between analytical solution and experiment result is attained.