Teal is a C library for computational fluid dynamics. It solves the compressible Euler and Navier-Stokes equations on 3D unstructured meshes using the finite-volume method. Conservation laws, flux schemes, and boundary conditions are interchangeable and can easily be extended to new physics.

Highlights

Meshes

• 3D unstructured mixed meshes
• Cartesian mesh generator
• Parallel reader for Gmsh
• Extensible to additional formats

Equations

• Compressible Euler and Navier-Stokes
• User-defined source terms
• Modular design for adding other conservation laws

Accuracy

• 2nd-order spatial accuracy
  • Least-squares gradient reconstruction
• Up to 3rd-order temporal accuracy
  • Low-storage explicit Runge-Kutta schemes
  • Implicit Euler with Newton-GMRES solver

Getting started

Clone and build:

git clone https://github.com/hheinzer/teal.git
cd teal
make

Executables are placed in the bin directory.

The best way to get started with teal is by running test cases in run. For example:

mpirun -n 4 bin/supersonic_wedge/run

Visualize the resulting VTKHDF files directly with ParaView.

The test cases demonstrate all capabilities of teal. If your editor supports "jump to definition", you can follow the program flow directly in the source. Function names and inline comments should be enough to understand what's going on.

Requirements

• Clang or GCC (set CC in Makefile) plus make
• MPI implementation (Open MPI or MPICH) with mpicc
• HDF5 built with MPI support (headers + libs)
• METIS and ParMETIS (ParMETIS must match your METIS build)
• Gmsh (to generate meshes from .geo files)
• ParaView (to visualize the results)

Performance

To assess the strong scaling of teal, the Taylor-Green vortex test case was run at three resolutions with varying numbers of MPI ranks for a fixed number of iterations. Speedup and efficiency are computed relative to the 128-rank baseline.

cells	iters	ranks	time	speedup	efficiency [%]
128^3	25000	128	40m 36.2s	1.00	100.0
128^3	25000	256	18m 35.8s	2.18	109.2
128^3	25000	512	9m 16.4s	4.38	109.5
128^3	25000	1024	5m 11.1s	7.83	97.9
256^3	3000	128	42m 48.9s	1.00	100.0
256^3	3000	256	21m 10.1s	2.02	101.1
256^3	3000	512	10m 24.5s	4.11	102.8
256^3	3000	1024	5m 11.3s	8.25	103.2
512^3	330	128	36m 57.3s	1.00	100.0
512^3	330	256	18m 14.7s	2.03	101.3
512^3	330	512	9m 37.3s	3.84	96.0
512^3	330	1024	5m 3.6s	7.30	91.3

Contributing

Contributions are welcome!

If you find a bug or have a feature request, please open an issue. To contribute code:

1. Fork the repository
2. Create a new branch for your feature or bug fix
3. Commit your changes and push to your fork
4. Open a pull request to the next branch

Acknowledgments

Teal is a successor to ccfd, which itself is a C rewrite of cfdfv. While teal builds on the concepts of these projects, it does not share any code with them.

The development of teal has been guided by foundational literature in computational fluid dynamics. Key resources include Computational Fluid Dynamics: Principles and Applications by J. Blazek and Riemann Solvers and Numerical Methods for Fluid Dynamics: A Practical Introduction by E. F. Toro.

License

Teal is licensed under the GPL-3.0 license.