Bouncing droplets onto a moving pool

Direct numerical simulation code infrastructure for three-dimensional drop impact onto a moving pool, supporting collaborative work with the Harris Lab at Brown. The code complements the associated arXiv preprint, and provides tools for parameter sweeps and visualisation.

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📌 Features

✅ Three-dimensional Navier-Stokes solver for drop-pool impact scenarios
✅ Parameter sweep support: resolution, drop velocity, pool velocity
✅ Two-phase, non-coalescing fluid volume implementation
✅ High-resolution output and animation capabilities
✅ Supplementary movies for publication and presentation

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🛠️ Installation

1. Requirements

• Basilisk (compiled with qcc)
• C compiler
• Visualization tools (e.g., ffmpeg, imagemagick, gnuplot)
• Recommended:

  sudo apt install ffmpeg imagemagick gnuplot

2. Clone the repository

git clone https://github.com/rcsc-group/BouncingDropletsMovingPool3D
cd BouncingDropletsMovingPool3D

3. Install Basilisk

See Basilisk’s installation page for instructions.

4. Running the code

After Basilisk is set up, run the driver code using the provided shell script:

sh run_master_example.sh

The script organizes outputs into folders with summaries and movies.

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⚙️ Key Simulation Options

Edit parameters across various layers to control:

• Drop velocity $U_{\textrm{drop}}$ (via the shell script)
• Pool velocity $U_{\textrm{pool}}$ (via the shell script)
• Resolution and domain size (via the shell script)
• Output frequency and visualization options (inside the driver code itself)

One key building block is the two-phase non-coalescing fluid volume implementation based on V. Sanjay’s code.

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📁 Folder Structure

.
├── DriverCode/                  # Main driver scripts and code for simulations
│   ├── 3D_Impact_Bounce.c       # Main simulation source code
│   ├── run_master_example.sh    # Shell script to run parameter sweeps and manage outputs
│   └── two-phaseDOD.h           # Header file for two-phase, non-coalescing fluid volume implementation
│
├── SupplementaryMovies/         # Supplementary movies and captions referenced in the manuscript
│   ├── SM1.mp4                  # Movie 1
│   ├── SM2.mp4                  # Movie 2
│   ├── SM3.mp4                  # Movie 3
│   ├── SM4.mp4                  # Movie 4
│   └── SM_Captions.txt          # Captions and descriptions for supplementary movies
│
├── LICENSE                      # License information
└── README.md                    # Project documentation

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📊 Outputs

Generates:

Summary files and movies in organized output folders:

• .mp4 animations for simulation data
• Data files (interface data coordinates) for further analysis

Visualisation can be toggled depending on your architecture and needs.

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📚 Citation

If you use this code or data in your work, please cite the associated preprint (for now):

Harris, D. M., Alventosa, L. F., Sand, O., Silver, E., Mohammadi, A., Sykes, T. C., ... & Cimpeanu, R. (2025). Bouncing to coalescence transition for droplet impact onto moving liquid pools. arXiv:2510.02220.

BibTeX:

@article{Harris2025Bouncing,
  title={Bouncing to coalescence transition for droplet impact onto moving liquid pools},
  author={Harris, D. M. and Alventosa, L. F. and Sand, O. and Silver, E. and Mohammadi, A. and Sykes, T. C. and ... and Cimpeanu, R.},
  journal={arXiv preprint arXiv:2510.02220},
  year={2025}
}

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🧑 Contributing

Feel free to:

• Fork this repo
• Open issues
• Submit pull requests

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