Zoomy

Flexible modeling and simulation software for free-surface flows.

Zoomy's main objective is to provide a convenient modeling interface for complex free-surface flow models. Zoomy transitions from a symbolic modeling layer to a numerical layer, compatible with a multitude of numerical solvers, e.g. NumPy, JAX, Firedrake, FEniCSx, OpenFOAM, and AMReX. Additionally, we support the preCICE coupling framework for some numerical backends, enabling convenient integration of our solver with your existing code.

Documentation

See the Zoomy documentation for the user guide, tutorials, API reference, and full installation / development setup.

Installation

• Try it now in your browser — interactive GUI at zoomylab.github.io/Zoomy/gui.
• Try a notebook in your browser — open the shallow-water Pyodide tour in JupyterLite (walks Model → SystemModel → NumericalSystemModel → C++ codegen → solve & plot, all running in the browser).
• Pip install the core:

  pip install zoomy_core

• Everything else (full repo clone, submodules, Apptainer / Docker, devcontainer, Conda/Mamba, backend-specific setup, development workflow) — see Documentation → Installation.

Backends

Zoomy's symbolic layer compiles to several solver backends. Each one has its own page in the documentation:

• NumPy
• JAX
• Firedrake
• PETSc DMPlex
• AMReX
• OpenFOAM
• FEniCSx

Note: Many backends are in an very early development status. If you are interested in a particular solver and you find no information, please contact us.

Testing

CI test reports for each backend are published with the docs site: see CI Reports.

License

The Zoomy source code is free open-source software, licensed under version 3 or later of the GNU Lesser General Public License (LGPLv3+). See LICENSE for full copying permissions.

Citation

@misc{steldermann_dimensionally_2025,
	author       = {Steldermann, Ingo and Bünning, Jonas and Pummer, Elena and Kowalski, Julia},
	editor       = {Pummer, Elena and Albayrak, Ismail},
	title        = {Dimensionally Reduced Shallow Moment Simulations of a Pumped-Storage Plant Tunnel System},
	publisher    = {ETH Zurich},
	date         = {2025},
	doi          = {10.3929/ETHZ-B-000727194},
	url          = {http://hdl.handle.net/20.500.11850/727194},
}

Zoomy or Shallow Moment Method related publication

@misc{steldermann_dimensionally_2025,
	author       = {Steldermann, Ingo and Bünning, Jonas and Pummer, Elena and Kowalski, Julia},
	editor       = {Pummer, Elena and Albayrak, Ismail},
	title        = {Dimensionally Reduced Shallow Moment Simulations of a Pumped-Storage Plant Tunnel System},
	publisher    = {ETH Zurich},
	date         = {2025},
	doi          = {10.3929/ETHZ-B-000727194},
	url          = {http://hdl.handle.net/20.500.11850/727194},
}

@incollection{steldermann_shallow_2024,
	author       = {Steldermann, Ingo and Torrilhon, Manuel and Kowalski, Julia},
	editor       = {Parés, Carlos and Castro, Manuel J. and Morales De Luna, Tomás and Muñoz-Ruiz, María Luz},
	title        = {Shallow Moment Equations—Comparing Legendre and Chebyshev Basis Functions},
	booktitle    = {Hyperbolic Problems: Theory, Numerics, Applications. Volume {II}},
	volume       = {35},
	pages        = {457--466},
	publisher    = {Springer Nature Switzerland},
	location     = {Cham},
	date         = {2024},
	isbn         = {978-3-031-55264-9},
	doi          = {10.1007/978-3-031-55264-9_39},
	url          = {https://link.springer.com/10.1007/978-3-031-55264-9_39},
}

@article{steldermann_shallow_2023,
	author       = {Steldermann, Ingo and Torrilhon, Manuel and Kowalski, Julia},
	title        = {Shallow Moments to Capture Vertical Structure in Open Curved Shallow Flow},
	journaltitle = {Journal of Computational and Theoretical Transport},
	volume       = {52},
	number       = {7},
	pages        = {475--505},
	date         = {2023-11-10},
	issn         = {2332-4309},
	doi          = {10.1080/23324309.2023.2284202},
	url          = {https://www.tandfonline.com/doi/full/10.1080/23324309.2023.2284202},
}

Acknowledgements

Zoomy builds on, integrates with, or uses logos from the following open-source projects. We gratefully acknowledge their authors and the licenses under which we use their work:

Project	Role in Zoomy	License	Notes
SymPy	symbolic modeling layer	BSD-3-Clause	logo by Fredrik Johansson, free use under the same terms as SymPy
NumPy	reference solver, arrays	BSD-3-Clause
JAX	zoomy_jax backend	Apache-2.0
Firedrake	zoomy_firedrake backend	LGPLv3+
FEniCSx / DOLFINx	zoomy_fenicsx backend	LGPLv3+
PETSc	DMPlex backend, Firedrake	BSD-2-Clause
AMReX	zoomy_amrex backend	BSD-3-Clause
OpenFOAM	OpenFOAM backend	GPL-3.0	logo: Carnby, CC BY-SA 4.0, via Wikimedia Commons
preCICE	coupling framework	LGPLv3+
Gmsh	mesh generation	GPLv2+
ParaView	post-processing	BSD-3-Clause	macros in tools/paraview_macros/
Jupyter Book	this documentation site	BSD-3-Clause
JupyterLite / Pyodide	in-browser notebook execution	BSD-3-Clause / MPL-2.0

If you spot a project we use but haven't credited, please open an issue.