ECOGEN: An open-source tool for multiphase, compressible, multiphysics flows

ECOGEN, a new open-source computational fluid dynamics code is presented. It is a multi-model tool devoted to the simulation of compressible flows. A large range of problems can be solved, from single-phase gas dynamics to multiphase, multiphysics flows including interface problems between pure fluids. This code is suited for strongly unsteady flows. The numerical solver of ECOGEN is implemented in a flexible structure making the code able to compute such complex flows on different kinds of discretization grids. The implemented hyperbolic solver is able to deal with Cartesian geometries as well as unstructured grids. A recent adaptive mesh refinement method is also implemented. Its numerical implementation is presented in detail to help the enthusiastic developer to contribute to this open-source project. Representative test cases are presented to show the tool abilities and to open the gate for future developments.

本文介绍了一款全新的开源计算流体动力学（Computational Fluid Dynamics, CFD）代码ECOGEN。该代码是专用于可压缩流动模拟的多模型工具，可求解从单相气体动力学到多相、多物理场流动的广泛问题，其中包含纯流体间的界面问题，尤其适用于强非定常流动的模拟。ECOGEN的数值求解器采用灵活的架构设计，使其能够在多种离散化网格上完成这类复杂流动的计算；所实现的双曲型求解器不仅可处理笛卡尔几何构型，还支持非结构化网格，此外还集成了最新的自适应网格细化（Adaptive Mesh Refinement, AMR）方法。本文详细阐述了其数值实现方案，以助力热心开发者参与该开源项目的贡献工作。文中还给出了典型测试算例，以展示该工具的性能，并为后续的开发工作开启探索之门。