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GPU-accelerated Lattice Boltzmann Simulations in Python

Lettuce is a Computational Fluid Dynamics framework based on the lattice Boltzmann method (LBM).

• GPU-Accelerated Computation: Utilizes PyTorch for high performance and efficient GPU utilization.
• Rapid Prototyping: Supports both 2D and 3D simulations for quick and reliable analysis.
• Advanced Techniques: Integrates neural networks and automatic differentiation to enhance LBM.
• Optimized Performance: Includes custom PyTorch extensions for native CUDA kernels.

Resources

• Documentation_
• Presentation at CFDML2021 - Paper | Preprint | Slides | Video | Code_

.. _Paper: https://www.springerprofessional.de/en/lettuce-pytorch-based-lattice-boltzmann-framework/19862378 .. _Documentation: https://lettuceboltzmann.readthedocs.io .. _Preprint: https://arxiv.org/pdf/2106.12929.pdf .. _Slides: https://drive.google.com/file/d/1jyJFKgmRBTXhPvTfrwFs292S4MC3Fqh8/view .. _Video: https://www.youtube.com/watch?v=7nVCuuZDCYA .. _Code: https://github.com/lettucecfd/lettuce-paper

Getting Started

To find some very simple examples of how to use lettuce, please have a look at the examples_. These will guide you through lettuce's main features. The simplest example is:

https://github.com/lettucecfd/lettuce/blob/ef9830b59c6ad50e02fdf0ce24cc47ea520aa354/examples/00_simplest_TGV.py#L6-L21

Please ensure you have Jupyter installed to run the Jupyter notebooks.

.. _examples: https://github.com/lettucecfd/lettuce/tree/master/examples

Installation

• Install the anaconda or miniconda package manager from https://www.anaconda.org

• Clone this repository from github and change to it::

  git clone https://github.com/lettucecfd/lettuce cd lettuce

• Update conda, create a new conda environment and activate it::

  conda update conda conda create -n lettuce conda activate lettuce

• Follow the recommendations at https://pytorch.org/get-started/locally/ to install pytorch based on your GPU's CUDA version. You may need to install the nvidia toolkit. You may follow the instructions at https://developer.nvidia.com/cuda-downloads. You may need to check the compatibility of your NVIDIA driver with the desired CUDA version: https://docs.nvidia.com/deploy/cuda-compatibility/. To get your CUDA version, run::

  nvcc --version

• For CUDA 12.1 (if supported by your GPU) use::

  conda install pytorch pytorch-cuda=12.1 -c pytorch -c nvidia

• Install the remaining dependencies. This will not include CUDA-support unless you installed pytorch-cuda!::

  conda activate lettuce conda install --file requirements.txt -c pytorch -c nvidia -c conda-forge

• NOTE: Sometimes, the installation does not properly set the CUDA_HOME variable. In this case, you may install cudatoolkit and set CUDA_HOME to the package directory (it should containa /bin/nvcc/ subdirectory!).

• If you want to only use lettuce, run the installation (from the lettuce base directory!). Ideally, use PEP 517::

  pip install --use-pep517 .

• If you are a developer, add the changeable-installation-flag (-e)::

  pip install --use-pep517 -e .

• Check out the convergence order, running on CPU::

  lettuce --no-cuda convergence

• Run the test cases::

  pytest tests

• For running a CUDA-driven LBM simulation on one GPU omit the --no-cuda. If CUDA is not found, make sure that cuda drivers are installed and compatible with the installed cudatoolkit (see conda install command above).

• Check out the performance, running on GPU::

  lettuce benchmark

Citation

If you use Lettuce in your research, please cite the following paper::

@inproceedings{bedrunka2021lettuce,
  title={Lettuce: PyTorch-Based Lattice Boltzmann Framework},
  author={Bedrunka, Mario Christopher and Wilde, Dominik and Kliemank, Martin and Reith, Dirk and Foysi, Holger and Kr{\"a}mer, Andreas},
  booktitle={High Performance Computing: ISC High Performance Digital 2021 International Workshops, Frankfurt am Main, Germany, June 24--July 2, 2021, Revised Selected Papers},
  pages={40},
  organization={Springer Nature}
}

Credits

We use the following third-party packages:

• pytorch_
• numpy_
• pytest_
• click_
• matplotlib_
• versioneer_
• pyevtk_
• h5py_
• mmh3_

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

.. Cookiecutter: https://github.com/audreyr/cookiecutter .. audreyr/cookiecutter-pypackage: https://github.com/audreyr/cookiecutter-pypackage

.. _pytorch: https://github.com/pytorch/pytorch .. _numpy: https://github.com/numpy/numpy .. _pytest: https://github.com/pytest-dev/pytest .. _click: https://github.com/pallets/click .. _matplotlib: https://github.com/matplotlib/matplotlib .. _versioneer: https://github.com/python-versioneer/python-versioneer .. _pyevtk: https://github.com/pyscience-projects/pyevtk .. _h5py: https://github.com/h5py/h5py .. _mmh3: https://github.com/hajimes/mmh3

License

• Free software: MIT license, as found in the LICENSE_ file.

.. _LICENSE: https://github.com/lettucecfd/lettuce/blob/master/LICENSE