Unified Momentum Model

This repository contains a reference implementation of the Unified Momentum Model presented in the associated manuscript titled Unified Momentum Model for Rotor Aerodynamics Across Operating Regimes. The Unified Momentum Model is a novel approach for modeling a yaw-misaligned actuator disk induction and outlet velocities, including negative and high thrust regimes.

The Unified Momentum Model is described in the associated publication available open-access in Nature Communications: Liew, J., Heck, K. S., & Howland, M.F. (2024) Unified momentum model for rotor aerodynamics across operating regimes. Nat Commun 15, 6658.

Installation

To install this Python package follow one of the following methods.

Direct installation from Github

To install directly from Github into the current Python environment, run:

pip install git+https://github.com/Howland-Lab/Unified-Momentum-Model.git

Install from cloned repository

If you prefer to download the repository first (for example, to run the example and paper figure scripts), you can first clone the repository, either using http:

git clone https://github.com/Howland-Lab/Unified-Momentum-Model.git

or ssh:

git clone git@github.com:Howland-Lab/Unified-Momentum-Model.git

then, install locally using pip using pip install . for the base installation, or pip install .[figures] to install the extra dependencies required to run the examples and paper figure scripts and notebooks:

cd Unified-Momentum-Model
pip install .[figures]

Usage

This repository contains

1. a Python package which implements the Unified Momentum Model (see the UnifiedMomentumModel folder)
2. working example scripts using the package in Python (see the examples folder)
3. Jupyter notebooks which recreate all figures in the manuscript (see the figures folder).

Package usage

A UnifiedMomentum model object can be instantiated and can be called to solve the actuator disk model model for a given local thrust coefficient, $C_T'$ and rotor yaw angle in radians, $\gamma$. Here is a short python script which demonstrates this:

from UnifiedMomentumModel.Momentum import UnifiedMomentum

model = UnifiedMomentum()
solution = model(Ctprime=2.0, yaw=0.0)

print(f"rotor-normal induction factor: {solution.an}")
print(f"streamwise outlet velocity: {solution.u4}")
print(f"lateral outlet velocity: {solution.v4}")
print(f"near-wake length: {solution.x0}")
print(f"outlet pressure: {solution.dp}")
print(f"Rotor power coefficient: {solution.Cp}")
print(f"Rotor thrust coefficient: {solution.Ct}")

Citation

This code repository can be cited as follows:

Liew, J., S. Heck, K., & Howland, M. F. (2023). Howland-Lab/Unified-Momentum-Model: Submission pre-release (v0.3.0). Zenodo. https://doi.org/10.5281/zenodo.10524066

Contributions

If you have suggestions or issues with the Unified Momentum Model, feel free to raise an issue or submit a pull request.