Free-surface flow is relevant to many researchers in water resources engineering, geohazard assessment, as well as coastal and river engineering. Many different free-surface models have been proposed, which span modeling complexity from the hydrostatic Saint-Venant equations to the Reynolds-averaged Navier-Stokes equations. Particularly efficient methods can be derived by depth-averaging, resulting in dimensionally reduced models. Typically, this yields hierarchies of models -- models with a variable system structure depending on the polynomial expansion of the flow variables -- that need to be analyzed and numerically solved. This description, analysis, and simulation are challenging, and existing software solutions only cover a specific subset of models generated by these hierarchies. We propose a new software framework to address this issue. Zoomy allows for an efficient description, symbolic analysis, and numerical solution of depth-averaged hierarchies of free-surface flow models. Zoomy handles a numerical discretization in one- and two-dimensional space on unstructured grids. With this framework, systematic evaluation of hierarchies of depth-averaged free-surface flows becomes feasible. Additionally, our open-source framework increases the accessibility of these depth-averaged systems to application engineers interested in efficient methods for free-surface flows.

翻译：自由表面流动是水资源工程、地质灾害评估以及海岸与河流工程领域众多研究者关注的核心问题。目前已提出多种自由表面流动模型，其建模复杂度涵盖从静水圣维南方程到雷诺平均纳维-斯托克斯方程的广泛范围。通过深度平均方法可推导出特别高效的数值方法，从而得到降维模型。这通常会产生模型层次结构——即根据流动变量的多项式展开而具有可变系统结构的模型系列——这些模型需要进行分析和数值求解。此类模型的描述、分析与仿真具有挑战性，现有软件解决方案仅能覆盖这些层次结构所生成模型的特定子集。为此，我们提出一种新的软件框架。Zoomy能够对深度平均自由表面流动模型层次结构进行高效描述、符号分析和数值求解。该软件支持非结构化网格上一维与二维空间的数值离散化。通过此框架，系统评估深度平均自由表面流动的层次结构成为可能。此外，我们的开源框架提升了这些深度平均系统对关注自由表面流动高效求解方法的应用工程师的可及性。