COMSOL Multiphysics vs FEST-3D

COMSOL Multiphysics is desktop software for simulating designs, devices, and processes in engineering, manufacturing, and scientific research. It supports single-physics and fully coupled multiphysics models, including user-defined physics descriptions and equations. Model Builder covers work from geometry and CAD through physics modeling, meshing, studies, optimization, solving, and visualization. Supported fields include electromagnetics, structural mechanics, acoustics, fluid flow, heat transfer, and chemical reactions.

Model Manager provides version control, storage, search, collaboration, permissions, and support for local or remote server databases. Application Builder lets experts create custom simulation interfaces for collaborators and customers; deploying those applications requires COMSOL Server or COMSOL Compiler. Interfacing products include LiveLink for MATLAB, Simulink, and Excel, as well as CAD links or import tools. The software supports Windows, macOS, and Linux, with offline access, authoring tools, 3D visuals, and data export. It is paid, with pricing on request, and a free trial is available. Customers contact COMSOL to evaluate requirements and choose a license; a sales representative responds within one business day.

FEST-3D is a Fortran 90 finite-volume computational fluid dynamics solver for Navier–Stokes flow problems on structured grids, developed for aerodynamics. It handles incompressible and compressible flows, including inviscid, laminar, transitional and turbulent cases. Users can select among flux schemes, reconstruction methods, time-integration options, turbulence models and transition models. MPI distributes computations across processors on one or more machines. The solver is free and open source under the GNU General Public License version 3.0, with source available from GitHub. Its installation script supports Ubuntu/Debian, CentOS and macOS, while manual installation instructions cover Linux. Building requires a Fortran compiler, an MPI library, CMake and Make. Tutorials in a separate repository address verification cases such as a smooth bump, lid-driven cavity, flat plates and an airfoil. FEST-3D writes VTK or Tecplot output for separate visualization tools. Grid generation and post-processing are outside the solver, and the project notes its halt/stop condition does not work with MPI.