PyVAWT: Vertical Axis Wind Turbine Aerodynamic Simulator

PyVAWT is a Python package developed for the aerodynamic simulation of Vertical Axis Wind Turbines (VAWTs) based on the Actuator Cylinder theory. The program incorporates high-fidelity aerodynamic loss models while maintaining low computational cost, allowing simulations to complete in just a few minutes on standard desktop computers.

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Key Features

• Fast Aerodynamic Modeling: Actuator Cylinder solver integrated with NeuralFoil for rapid airfoil polar predictions via JIT compilation and neural networks.
• Flexible Modules: Support for single turbine simulations (with 2D/3D options and advanced aerodynamic submodels) and multiple coupled turbines (2D aerodynamic interaction).
• Automated Parametric Sweep: Automated execution of parameter combinations (chord, solidity, wind speed, and airfoil profiles).
• Physical Submodels: Support for tip loss (Tip Loss), dynamic stall (Dynamic Stall), and flow curvature (Flow Curvature) corrections.
• Comprehensive Export Options: Generation of data tables (.dat, .csv), performance curves ($C_P \times \text{TSR}$, $C_T \times \text{TSR}$), and azimuthal distributions ($C_P(\theta)$).

Important Note on Parametric Analysis: The automated parametric sweep functionality (providing array inputs for chord, solidity, Vinf, etc.) is exclusively available for single-turbine simulations in 2D mode (simulation3d.enabled: false). The 3D and Multiple Turbines modules operate strictly with scalar inputs per run.

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Project Origin & Funding

This software was developed as part of an academic research project focused on the aerodynamic modeling and optimization of vertical axis wind turbines.

This work was supported by the São Paulo Research Foundation (FAPESP).

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Requirements & Installation

Minimum Requirements

• Operating System: Linux, macOS, or Windows.
• Python: Version 3.13 or higher.
• Environment Manager: uv (recommended for fast dependency management).

Installation Steps

1. Clone the repository:

   git clone [https://github.com/your-username/pyvawt.git](https://github.com/your-username/pyvawt.git)
   cd pyvawt

2. Create the virtual environment and install dependencies via uv:

   uv sync

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Configuration Files (YAML)

The program uses hierarchical configuration files to define simulation parameters.

1. Single Turbine (config.yaml)

turbine:
  r: 1.0          # Rotor radius [m]
  H: 2.0          # Rotor height [m]
  twist: 0.0      # Twist angle [deg]
  delta: 0.0      # Pitch angle [deg]
  chord: 0.15     # Blade chord [m] (or array for 2D sweeps)
  B: 2            # Number of blades
  solidity: 0.3   # Solidity [-] (or array for 2D sweeps)
  centerX: 0.0
  centerY: 0.0
  Omega: 15.0     # Angular velocity [rad/s]
  ntheta: 36

environment:
  Vinf: 10.0      # Free-stream wind speed [m/s]
  rho: 1.225      # Air density [kg/m³]
  mu: 1.789e-5    # Dynamic viscosity [Pa·s]

solver:
  fixed_parameter: "vinf" # "vinf" or "omega"
  tsr:
    min: 1.0
    max: 6.0
    n_points: 20
  method: "neuralfoil"
  neuralfoil:
    airfoil: ["NACA0012"]
    model_size: "medium"
  simulation3d:
    enabled: false # Requires 'false' for parametric sweeps

submodels:
  tip_loss: true
  dynamic_stall: false
  flow_curvature:
    enabled: true
    normalized_hook_point: 0.5

output:
  save: true
  save_config: true
  save_plot: true
  data_file:
    format: "dat" # "dat" or "csv"
    include_header: true
  plot_image:
    format: "png" # "png" or "eps"
    dpi: 300

2. Multiple Turbines (config_multiple.yaml)

For multiple turbine arrays, specify the number of rotors and their spatial coordinates in array format:

turbine:
  centerX: [0.0, 3.0] # X positions of turbines [m]
  centerY: [0.0, 0.0] # Y positions of turbines [m]

solver:
  num_turbines: 2

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Running Simulations

Simulations are executed from the root directory using uv:

Single Turbine Simulation

uv run python3 -m src.pyvawt.single.main

To inspect all loaded configuration parameters prior to execution:

uv run python3 -m src.pyvawt.single.main --show-config

Multiple Turbines Simulation

uv run python3 -m src.pyvawt.multiple.main

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Output Structure (Results)

Upon completion, a timestamped directory is created inside the results folder containing:

results/
└── YYYYMMDD_HHMMSS_run/
    ├── config_used.yaml          # Copy of the configuration file used
    ├── results_NACA0012.dat      # Numerical results (TSR, Cp, Ct)
    ├── cp_curve_NACA0012.png     # Cp vs TSR plot
    └── cp_theta_NACA0012.png     # Azimuthal distribution Cp(theta) plot

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Repository Structure

pyvawt/
├── config/
│   ├── config.yaml              # Default configuration (Single Turbine)
│   └── config_multiple.yaml     # Default configuration (Multiple Turbines)
├── pyproject.toml           # Project configuration & dependencies
├── uv.lock                  # uv lockfile
├── README.md                # Main documentation
└── src/
    └── pyvawt/
        ├── single/          # Single turbine module (2D/3D/Parametric)
        │   └── main.py
        └── multiple/        # Multiple turbine array module (Only 2D)
            └── main.py

License

This project is licensed under the MIT License - see the LICENSE file for details.