DCTwin — Data Center Digital Twin CFD Toolbox

Automated CFD Simulation Framework for Data Center Thermal Analysis

---

DCTwin is an open-source Python framework that automates OpenFOAM thermal simulation for data center environments. Given a JSON simulation manifest (.cfdrun) and pre-exported STL geometry files, DCTwin handles the full CFD pipeline automatically.

Key Features

• JSON-driven workflow -- Data center layout (racks, servers, ACUs, raised floor, containment) defined in a .cfdrun manifest with pre-exported multi-solid STL files
• Automated CFD pipeline -- blockMesh -> snappyHexMesh -> boundary conditions -> buoyantBoussinesqSimpleFoam -> post-processing
• Domain-specific automation:
  • Automatic U-slot server positioning and inlet/outlet face generation
  • Air leakage modeling with auto-computed Darcy-Forchheimer porous media
  • Raised floor with perforated tile openings
  • Cold/hot aisle containment support
• Modular pipeline -- Run STL-only, mesh-only, or solve-only stages independently

Prerequisites

• Python 3.10+
• Conda (Miniconda or Anaconda)
• OpenFOAM v2406 installed and available on PATH

Installation

git clone https://github.com/CAP-GDCR/Dctwin-CFD.git
cd Dctwin-CFD
bash setup_env.sh
conda activate dctwin

Quick Start

# Full pipeline (mesh -> solve) — runs the triangle_room example case
python -m dctwin.runner.run_cfd --from-cfdrun case/triangle_room/model/triangle_room.cfdrun

# Or run stages independently:
python -m dctwin.runner.run_cfd --from-cfdrun case/triangle_room/model/triangle_room.cfdrun --mesh-only   # Mesh only
python -m dctwin.runner.run_cfd --from-cfdrun case/triangle_room/model/triangle_room.cfdrun --solve-only  # Solve only

Example Cases

Case	Description
case/triangle_room/	Triangular room layout (good first example)
case/slab_floor/	Single-slab data center with raised floor
case/rack_leakage/	Air leakage modeling through unoccupied rack U-slots
case/standard_dc/	Standard data center topology (24 racks, 3 ACUs)
case/conference_demo/	Large conference demo case

Architecture

.cfdrun manifest + STL files
    |
    v
+------------------------------+
|  STLGenRunner                |
|  Validates JSON manifest,    |
|  discovers STL geometry      |
+------------------------------+
    |
    v
+------------------------------+
|  MeshGenerator               |
|  blockMesh -> snappyHexMesh  |
|  + topoSet + createBaffles   |
+------------------------------+
    |
    v
+------------------------------+
|  FieldGenerator              |
|  Auto boundary conditions    |
|  (velocity, temperature,     |
|   pressure, turbulence)      |
+------------------------------+
    |
    v
+------------------------------+
|  OpenFOAM Solver             |
|  buoyantBoussinesqSimpleFoam |
|  (steady-state RANS k-e)    |
+------------------------------+
    |
    v
    CFD Results (T, U, p fields)

Project Structure

Dctwin-CFD/
├── src/dctwin/                # Core Python package
│   ├── runner/                # Pipeline orchestration
│   │   ├── stlgen_runner.py   # STLGenRunner (main orchestrator)
│   │   ├── run_cfd.py         # CLI entry point
│   │   ├── cfdproj_schema.py  # Pydantic v2 schema validation
│   │   ├── bridge_bc.py       # Boundary condition registry
│   │   ├── fields.py          # FieldGenerator (boundary conditions)
│   │   └── postprocess.py     # Result extraction
│   ├── third_parties/foam/    # OpenFOAM integration
│   │   └── template/          # Jinja2 OpenFOAM dict templates
│   └── utils/                 # Shared utilities
├── case/                      # Example simulation cases
└── docs/                      # Documentation (MkDocs)

Documentation

mkdocs serve

Contributing

Contributions are welcome! Please read the Contributing Guide before submitting a pull request.

License

This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0). See the LICENSE file for details.

Acknowledgments

Developed by the NTU-CAP research group at Nanyang Technological University, Singapore.

This repository contains only the DCTwin backend currently. The DCTwin GUI for visual modeling and case setup is under active development and is planned for open-source release soon.