Advantages of using adaptive remeshing and parallel processing for modelling biodegradation in groundwater
Advantages of using adaptive remeshing and parallel processing for modelling biodegradation in groundwater
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DOI：
10.1016/j.advwatres.2005.01.003
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发表时间：
2005-11
影响因子：
4.7
通讯作者：
I. Watson;R. Crouch;P. Bastian;S. Oswald
中科院分区：
文献类型：
--
作者：
I. Watson;R. Crouch;P. Bastian;S. Oswald
地下水中的生物降解羽流的典型特征是边缘的相对反应区和核心的反应区较少。如果一个模型要用来改进对羽流的概念理解，就需要在边缘进行高度的改进。处理潜在的高计算需求的两种策略是(I)并行处理，其中工作负载在多个处理器之间分担，以及(Ii)局部自适应重新网格化，其中网格的精细化区域跟踪穿过区域的移动羽流。偏微分方程工具箱UG(非结构网格)提供了先进的数值工具，包括自适应重新划分网格、稀疏矩阵存储方案和多重网格求解器。它在并行处理环境中包含了许多这样的功能。本文报道了UG模拟野外尺度反应生物地球化学的最新进展，包括Monod动力学、NAPL溶解、矿物沉淀/溶解和离子交换。用全耦合方法求解了非线性多组分反应输运系统。测试用例已用于验证新功能。文中举例说明了该方法在三维野外场地中的应用。结果表明，自适应重网格和并行处理都可以提高效率，进而促进一组更复杂的物种和反应的并入，从而增强对羽流过程的理解。
Biodegrading plumes in groundwater are often typified by relatively reactive zones around the fringes and less reactive zones in the core. A high degree of refinement is required at the fringes if a model is to be of use in improving the conceptual understanding of plumes. Two strategies for dealing with the potentially high computational demands are (i) parallel processing, where the workload is shared between multiple processors, and (ii) locally adaptive remeshing, where a refined area of the grid tracks the moving plume fringes through the domain. The partial differential equation toolbox, UG (Unstructured Grids) offers advanced numerical tools including adaptive remeshing, sparse matrix storage schemes, and multigrid solvers. It embraces many of these features within a parallel processing environment. This paper reports on a recent development of UG to simulate field scale reactive biogeochemistry including Monod kinetics, NAPL dissolution, mineral precipitation/dissolution and ion exchange. The non-linear multicomponent reactive transport system is solved with the fully coupled method. Test cases have been used for verification of the new capability. The paper illustrates an application to a 3D field site. It is demonstrated that both adaptive remeshing and parallel processing can improve efficiency and in turn facilitate the incorporation of a more complex set of species and reactions such that understanding of plume processes is enhanced.