AhmedML Dataset¶

The AhmedML dataset is a publicly available dataset in Hugging Face licensed as CC BY-SA 4.0 and distributed separately to MLSimKit. It is a collection of high-fidelity CFD simulations showing different geometric variants of a body for automotive aerodynamic modeling. Please see the Hugging Face dataset for additional details.

Downloading the training data (45G)¶

You can download the data required for the training tutorials using Python with the huggingface_hub package:

pip install huggingface_hub

Then use this Python code to download the dataset:

from huggingface_hub import snapshot_download

snapshot_download(
    repo_id="neashton/ahmedml",
    repo_type="dataset",
    local_dir="/path/to/dataset",
    allow_patterns=[
        "run_*/ahmed*.stl",
        "run_*/images/*",
        "run_*/boundary*.vtp",
        "run_*/force_mom_*.csv"
    ]
)

Replace /path/to/dataset to your own directory.

The Surface tutorial has a step to download a smaller subset of data. The entire dataset includes high-resolution meshes not required for training.

Understanding the Dataset¶

The dataset contains 500 cases, each representing a unique geometry variant. The cases are organized into separate folders named run_1 to run_500, one for each simulation case. The variability in geometry across the 500 cases leads to a diverse set of flow physics, making this dataset well-suited for machine learning model development.

Within each run folder is a standard set of files:

run_1/
├── ahmed.stl
├── boundary_1.vtp
├── force_mom_1.csv
├── force_mom_varref_1.csv
├── geo_parameters_1.csv
├── images
│   ├── CpT
│   │   ├── run_*.png
│   ├── UxMean
│   │   ├── run_*.png
├── slices
│   ├── slice_*.vtp
└── volume_1.vtu

ahmed_<run #>.stl - The surface geometry definition in STL format
boundary_<run #>.vtp - Simulation results on the surface
volume_<run #>.vtu - Volumetric simulation outputs
force_mom_<run #>.csv - Time-averaged force and moment coefficients
force_mom_varref_<run #>.csv - Time-averaged force and moment coefficients using unique reference area per geometry
images - Folder containing slice images through the volume
slices - Folder containing slice vpt files rotated around the x, y, and z axes

The slice images show simulation variables like pressure and velocity captured on 2D planes along the X, Y and Z axes. Multiple views are available.

Slice Image Views¶

The images folder within each case contains subfolders organizing the slice images by simulation output variable.

Within each variable folder (e.g. CpT, UxMean), there are multiple image sets showing different sliced views through the volume.

The main image sets are:

X-Axis Slices

Filename pattern: run_*-X-*.png

These are slices along the X-axis, showing the YZ-plane at different X positions. Useful for visualizing the flow as it passes over the geometry from front to back.