A Python toolkit for CFD pre-processing, mesh generation, and post-processing.

Cassiopee is a collection of 19 Python modules developed by ONERA, the French Aerospace Lab, for computational fluid dynamics (CFD) workflows. Cassiopee has been in development at ONERA’s Aerodynamics, Aeroelasticity, and Acoustics Department (DAAA) since the early 2000s and has been open-source since 2024.

Its modular API provides building blocks for geometry processing, mesh generation and transformation, data conversion, and solution post-processing. Cassiopee is solver-agnostic and supports workflows involving structured and unstructured meshes, including advanced overset-grid and immersed-boundary methods.

Explore the documentation, run an example, ask for help, or install Cassiopee using the links below.

• Documentation
• Tutorials (work in progress)
• Release notes
• Report a bug or ask a question

What can you do with Cassiopee?

Cassiopee provides…