Validation of 2D shock capturing flood models around a surcharging manhole

This work offers a detailed validation of finite volume (FV) flood models in the case where horizontal floodplain flow is affected by sewer surcharge flow via a manhole. The FV numerical solution of the 2D shallow water equations is considered based on two approximate Riemann solvers, HLLC and Roe, on both quadrilateral structured and triangular unstructured mesh-types. The models are validated against a high resolution experimental data-set obtained using a physical model of a sewer system linked to a floodplain via a manhole. It was verified that the sensitivity of the models is inversely proportional to the surcharged flow/surface inflow ratio, and therefore requires more calibration from the user especially when concerned with localised modelling of sewer-to-floodplain flow. Our findings provide novel evidence that shock capturing FV-based flood models are applicable to simulate localised sewer-to-floodplain flow interaction.

本研究针对通过检查井受污水管满溢水流影响的洪泛平原横向水流场景，对有限体积法（Finite Volume, FV）洪水模型开展了详尽的验证工作。本次研究采用两种近似黎曼解算器（HLLC与Roe），分别在四边形结构化网格与三角形非结构化网格两种网格类型下，对二维浅水方程的有限体积数值解法进行了探究。本研究以通过检查井连接洪泛平原与污水管网的物理模型所获取的高分辨率实验数据集为基准，对上述模型进行了验证。经验证，模型的灵敏度与满溢水流/地表入流比率成反比，因此用户需要进行更多的参数校准，尤其是在针对污水管至洪泛平原水流的局域化建模场景中。本研究的结论提供了新的佐证，证明基于有限体积法的激波捕捉型洪水模型可用于模拟污水管与洪泛平原之间的局域化水流相互作用。