NekMesh: An open-source high-order mesh generation framework

High-order spectral element simulations are now becoming increasingly popular within the computational modelling community, as they offer the potential to deliver increased accuracy at reduced cost compared to traditional low-order codes. However, to support accurate, high-fidelity simulations in complex industrial applications, there is a need to generate curvilinear meshes which robustly and accurately conform to geometrical features. This is, at present, a key challenge within the mesh generation community, with only a few open-source tools able to generate curvilinear meshes for complex geometries. We present NekMesh: an open-source mesh generation package which is designed to enable the generation of valid, high-quality curvilinear meshes of complex, three-dimensional geometries for performing high-order simulations. We outline the software architecture adopted in NekMesh, which uses a pipeline of processing modules to provide a flexible, CAD-independent high-order mesh processing tool, capable of both generating meshes for a wide range of use cases, as well as post-processing linear meshes from a range of input formats for use with high-order simulations. A number of examples in various application areas are presented, with a particular emphasis on challenging aeronautical and fluid dynamics test cases.

高阶谱元素模拟在计算建模领域正日益受到重视，因其相较于传统低阶代码，在降低成本的同时，有望提供更高的精度。然而，为了支持复杂工业应用中精确、高保真度的模拟，有必要生成能够稳健且精确地符合几何特征的曲线网格。目前，这在网格生成领域是一个关键挑战，仅有少数开源工具能够为复杂几何形状生成曲线网格。我们推出了NekMesh：一款开源的网格生成软件包，旨在实现生成复杂、三维几何形状的有效、高质量曲线网格，以执行高阶模拟。我们概述了NekMesh采用的软件架构，该架构通过一系列处理模块的管道，提供了一种灵活、与CAD无关的高阶网格处理工具，能够为广泛的用例生成网格，同时还能从多种输入格式中后处理线性网格，以供高阶模拟使用。我们展示了多个应用领域的实例，特别强调了具有挑战性的航空和流体动力学测试案例。