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).
• Install the published packages (NumPy and JAX backends): Get started → Install.
• Containers (Docker / Apptainer, CPU and GPU, AMReX, OpenFOAM): Get started → Containers.
• Develop Zoomy (clone with submodules, editable installs, local images): Developer guide → Developer installation.

Backends

Zoomy's symbolic layer compiles to several solver backends. NumPy, JAX, AMReX and OpenFOAM share one page in the documentation: Solver backends.

Testing

The test matrix, the timings and the CI status are on the Testing page of the documentation.

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

BibTeX

@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},
}

Plain text

Steldermann, I., Bünning, J., Pummer, E., Kowalski, J. (2025). Dimensionally Reduced Shallow Moment Simulations of a Pumped-Storage Plant Tunnel System. ETH Zurich. Edited by E. Pummer and I. Albayrak. https://doi.org/10.3929/ETHZ-B-000727194

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

The full list of third-party software, numerical methods and models Zoomy builds on, with how to cite each, is on the Acknowledgements page of the documentation. The BibTeX for all of them is in docs/book/references/third_party.bib.

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.