| 曾季才,查元源,杨金忠.大区域含水层中局部复杂水流过程的多尺度模拟[J].水利学报,2017,48(9):1064-1072 |
| 大区域含水层中局部复杂水流过程的多尺度模拟 |
| Multi-scale simulation of the local-scale complex flow processes in a large-scale groundwater system |
| 投稿时间：2016-11-08 |
| DOI：10.13243/j.cnki.slxb.20161167 |
| 中文关键词: 区域尺度 地下水 局部尺度复杂水流过程 多尺度模拟 耦合模型 |
| 英文关键词: regional-scale groundwater local-scale complex flow multi-scale simulation coupled model |
| 基金项目:国家自然科学基金项目（51479143）；内蒙古自治区水利科技计划项目（[2014]117-02） |
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| 中文摘要: |
| 精细刻画带有小尺度特征的局部复杂水流运动过程，是大区域地下水流运动数值模拟的重要议题。本文建立了一种能进行多时空尺度数值离散的三维地下水流运动耦合模型，用以获取全区域大尺度解及多子域小尺度高精度解。模型采用基于达西定律的三维水头插值算法，以实现多空间尺度模型耦合；同时，针对局部复杂水流条件，进行小尺度模型边界水头二阶时间曲线拟合及自适应时间步长插值，以实现多时间尺度模型耦合；此外，在局部问题的求解上支持任意边界形状及空间范围内的多个自由加密子网格离散，从而充分节省计算成本并保证计算精度。本文以通用地下水模型求解软件MODFLOW在高密度时空网格上的解作为参照解，对比分析了模型在多时空尺度、非匹配自由网格问题中的求解精度。相比传统局部加密或全局加密模型方法，本文模型能大幅度减小矩阵规模和求解工作量；相比传统局部加密多网格耦合模型，本文模型能更精确地刻画局部尺度的复杂水流运动过程。本文模型耦合方案可作为大区域含水层中精细刻画小尺度复杂水流过程的高效数值工具。 |
| 英文摘要: |
| It is a long lasting cost-benefit issue to accurately simulate the complex groundwater flow phe-nomena with small-scale properties within a large-scale aquifer. This work proposes a three-dimensional coupling scheme for groundwater flow simulation with multi-scale spatial and temporal discretization to solve the large-scale model within the entire domain and meanwhile multiple small-scale models within the us-er-specified sub-domains. The Darcy-based three-dimensional head interpolation scheme is utilized to deliv-er messages among models at different spatial scales. For each self-adaptive time-step marching of the small scale models, a second-order fitting curve is obtained to approximate the sharp boundary head change, which is caused by the large hydraulic gradient in the sub-domains. The coupling model allows multiple sub-models to be solved with resolution-free grids inside the arbitrarily shaped and partitioned boundaries, which largely reduces the computational costs and ensures the accuracy at small scale. A com-parative analysis is conducted in hypothetical homogeneous aquifers to verify the computational efficiency of the coupling model within the non-match and free-resolution grids. The results of the test cases show obvi-ous advantages against traditional groundwater model by largely cutting down the nodal points to be solved while retaining the original precision level over the sub-domains. |
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