The finite element method offers attractive methods for the numerical solution of coupled field problems arising in sensors and actuator simulations of various physical domains, like electrodynamics, mechanics, and thermodynamics. With this application perspective and being open, accessible, and fast implementations are possible, openCFS was launched in 2020. It provides an open-source framework for implementing partial differential equations using the finite element method. In particular, the acoustic module is part of active development, including several key methods. These methods include the perfectly-matched layer technique, non-confirming interface formulations, Lagrangian basis function, Legendre basis functions, spectral element formulations, a nodal element type, edge-based element type (aeroacoustic post-processing), absorbing boundary conditions, frequency dependent-material for time-harmonic and time-dependent simulations. Time-dependent simulations, time-harmonic simulations, and eigenvalue simulations are supported. Several variants of acoustic equations are implemented, including the relevant source terms and wave operators for aeroacoustics. The package includes rotating domains and non-conforming interfaces for fan noise simulations. It also contains an API to the Python3 package pyCFS. This paper presents openCFS with a focus on the acoustic module.

翻译：有限元方法为传感器与执行器仿真中出现的多物理场耦合问题（如电动力学、力学和热力学）提供了极具吸引力的数值求解方案。基于这一应用视角，并致力于实现开放、易获取且高效的代码实现，openCFS于2020年正式发布。该软件提供了一个基于有限元方法实现偏微分方程求解的开源框架。其中，声学模块正处于积极开发阶段，已集成多项关键方法，包括完美匹配层技术、非协调界面公式、拉格朗日基函数、勒让德基函数、谱元公式、节点单元类型、基于边的单元类型（用于气动声学后处理）、吸收边界条件，以及适用于时谐与瞬态仿真的频变材料模型。该模块支持瞬态仿真、时谐仿真和特征值仿真，实现了多种声学方程变体，涵盖气动声学相关的源项与波动算子。软件包包含用于风扇噪声仿真的旋转域与非协调界面处理功能，并提供了与Python3软件包pyCFS的应用程序接口。本文重点介绍openCFS的声学模块。