Ben-Zvi Rami, Jiang Shidong, Scher Harvey, Berkowitz Brian
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, NJ, 07102.
Ground Water. 2019 May;57(3):479-484. doi: 10.1111/gwat.12813. Epub 2018 Aug 22.
An exposition is given of a finite-element method (FEM) software package to calculate solutions for the continuous time random walk (CTRW) integro-differential equation for non-Fickian (and Fickian) conservative or reactive transport in disordered media. The solutions encompass one-dimensional/two-dimensional (1D/2D) breakthrough curves and spatial concentration profiles for general geometry and grid. The velocity field, used as input to the 2D solutions, may also be calculated by applying a compatible Darcy flow 2D solver. The software enables both "forward" modeling (1D/2D) and "inverse" (best-fit) modeling (1D) of experimental data. Various inlet and outlet boundary conditions are implemented. The CTRW-FEM Package is freely downloadable and contains a User's Guide, source and executable files, and accompanying files with easy-to-use format, including descriptions of input/output files and pre- and post-processing. Several examples are provided to clearly demonstrate how to work with the CTRW-FEM Package in many typical analyses. The CTRW-FEM Package also allows users to adapt the software to specific needs, such as, for example, first- and second-order chemical reactions.
介绍了一种有限元方法（FEM）软件包，用于计算无序介质中非菲克（和菲克）保守或反应输运的连续时间随机游走（CTRW）积分微分方程的解。这些解包括一般几何形状和网格的一维/二维（1D/2D）突破曲线和空间浓度分布。用作二维解输入的速度场也可以通过应用兼容的达西流二维求解器来计算。该软件能够对实验数据进行“正向”建模（1D/2D）和“反向”（最佳拟合）建模（1D）。实现了各种入口和出口边界条件。CTRW-FEM软件包可免费下载，包含用户指南、源文件和可执行文件，以及格式易于使用的配套文件，包括输入/输出文件的描述以及预处理和后处理。提供了几个示例，以清楚地展示在许多典型分析中如何使用CTRW-FEM软件包。CTRW-FEM软件包还允许用户根据特定需求对软件进行调整，例如一阶和二阶化学反应。
