Name: ahmedml
Creator: Neil Ashton
License: https://choosealicense.com/licenses/cc-by-sa-4.0/

AhmedML: High-Fidelity Computational Fluid Dynamics dataset for incompressible, low-speed bluff body aerodynamics

Contact:

Neil Ashton (NVIDIA) - [email protected]

website:

https://caemldatasets.org

Summary:

This dataset contains 500 different geometric variations of the Ahmed Car Body - a simplified car-like shape that exhibits many of the flow topologies that are present on bluff bodies such as road vehicles. The dataset contains a wide range of geometries that exhibit fundamental flow physics such as geometry and pressure-induced flow separation of flows as well as 3D vortical structures. Each variation of the Ahmed car body were run using a time-accurate hybrid Reynolds-Averaged Navier-Stokes (RANS) - Large-Eddy Simulation (LES) turbulence modelling approach using the open-source CFD code OpenFOAM. The dataset contains both surface boundary, 3D volume, geometry STL and forces/moments in open-source formats (.vtu,.vtp).

CFD Solver:

All cases were run using the open-source finite-volume code OpenFOAM v2212. Each case was run transiently for approximately 80 convective time units (CTU) on meshes of approximately 20M cells. Please see the paper for full details on the code and validation:

How to cite this dataset:

In order to cite the use of this dataset please cite the paper below which contains full details on the dataset. It can be found here: https://arxiv.org/abs/2407.20801

@article{ashton2024ahmed, title = {{AhmedML: High-Fidelity Computational Fluid Dynamics dataset for incompressible, low-speed bluff body aerodynamics}}, year = {2024}, journal = {arxiv.org}, author = {Ashton, Neil and Maddix, Danielle and Gundry, Samuel and Shabestari, Parisa} }

Files:

Each folder (e.g run_1,run_2...run_"i" etc) corresponds to a different geometry that contains the following files where "i" is the run number:

ahmed_i.stl : geometry stl (~5mb):
geo_parameters_1.csv (missing run 500): parameters that define the geometry
boundary_i.vtp : Boundary VTP (~500mb)
volume_i.vtu : Volume field VTU (~5GB)
force_mom_i.csv : forces (Cd,Cl) time-averaged with constant reference area
force_mom_varref_i.csv : forces (Cd,Cl) time-averaged with varying reference area
slices : folder containing .vtp slices in x,y,z that contain flow-field variables
images : (folder) that contains images of the following variables (CpT, UxMean) for slices of the domain in the X,Y & Z locations. In addition we provide:
force_mom_all.csv : run, cd,cl for all runs in a single file
force_mom_varref_all.csv : run, cd,cl for all runs in a single file with varying reference area
geo_parameters_all.csv : all the geometry parameters for each run inside a single file
ahmedml.slvs : SolveSpace input file to create the parametric geometries
stl : folder containing stl files that were used as inputs to the OpenFOAM process
openfoam-casesetup.tgz : complete OpenFOAM setup that can be used to extend or reproduce the dataset
validation : folder containing full outputs from all four mesh levels that were used to validate the methodology

Downloads

The dataset is now available on HuggingFace. Below are some examples of how to download all or selected parts of the dataset. Please refer to the HuggingFace documentation for other ways to accessing the dataset and building workflows.

Example 1: Download all files (~2TB)

Please note you'll need to have git lfs installed first, then you can run the following command:

git clone [email protected]:datasets/neashton/ahmedml

Example 2: only download select files (STL,images & force and moments):

Create the following bash script that could be adapted to loop through only select runs or to change to download different files e.g boundary/volume.

#!/bin/bash

# Set the paths
HF_OWNER="neashton"
HF_PREFIX="ahmedml"

# Set the local directory to download the files
LOCAL_DIR="./ahmed_data"

# Create the local directory if it doesn't exist
mkdir -p "$LOCAL_DIR"

# Loop through the run folders from 1 to 500
for i in $(seq 1 500); do
    RUN_DIR="run_$i"
    RUN_LOCAL_DIR="$LOCAL_DIR/$RUN_DIR"

    # Create the run directory if it doesn't exist
    mkdir -p "$RUN_LOCAL_DIR"

    # Download the ahmed_i.stl file
    wget "https://huggingface.co/datasets/${HF_OWNER}/${HF_PREFIX}/resolve/main/$RUN_DIR/ahmed_$i.stl" -O "$RUN_LOCAL_DIR/ahmed_$i.stl"

    # Download the force_mom_i.csv file
    wget "https://huggingface.co/datasets/${HF_OWNER}/${HF_PREFIX}/resolve/main/$RUN_DIR/force_mom_$i.csv" -O "$RUN_LOCAL_DIR/force_mom_$i.csv"

done

Acknowledgements

OpenFOAM solver and workflow development by Neil Ashton (Amazon Web Services, now NVIDIA)
Geometry parameterization by Samuel Gundry (Amazon Web Services) and Parisa Shabestari (Amazon Web Services)
Guidance on dataset preparation for ML by Danielle Madix (Amazon Web Services)
Simulation runs, HPC setup and dataset preparation by Neil Ashton (Amazon Web Services, now NVIDIA)

License

This dataset is provided under the CC BY SA 4.0 license, please see LICENSE.txt for full license text.

version history:

15/02/2025 - files uploaded to HuggingFace
12/11/2024 - added validation folder that contains the full output from all four mesh levels that were used to validate the methodology used.
04/08/2024 - updates to the file description and arxiv paper
05/06/2024 - global forces/geo added for all runs
01/05/2024 - force/moments corrected (prior version had incorrect Cs data)
18/04/2024 - draft version produced