RM2 CACTUS simulation case

This repository contains configuration files and scripts for modeling the DOE/Sandia RM2 cross-flow turbine with [CACTUS](http://energy.sandia.gov/energy /renewable-energy/wind-power/wind-resources/wind-software-downloads/cactus- software-download/). Note that the simulation may require an unreleased, non-backwards-compatible version of CACTUS, as indicated by the cactus submodule.

Getting started

Runs are automated and post-processed with Python. It is recommended users download and install the Anaconda Python distribution (3.5).

This project has been mostly run on Linux. On an Ubuntu-like system, all non-Python dependencies can be installed with

sudo apt-get install gfortran libblas-dev liblapack-dev octave

To download and compile CACTUS and related tools along with this repo, execute

git clone https://github.com/UNH-CORE/RM2-CACTUS.git --recursive

then run

make cactus

Note that if this repo was cloned without the --recursive option, the submdules can be cloned with

git submodule update --init --recursive

One additional Python plotting dependency (beyond Anaconda) can be installed with

pip install pxl

Usage

Executing CACTUS is done with run.py. To see usage and options, execute

python run.py -h

A similar script, plot.py is used for plotting the results.

Examples

Run at a single tip speed ratio without dynamic stall:

python run.py --tsr=3.1 --dynamic-stall=0

Calculate turbine performance curve:

python run.py -p tsr 1.1 4.7 0.5

Run time step dependence parameter sweep:

python run.py -p nti 8 65 4

Run parameter sweep for number of blade elements:

python run.py -p nbelem 4 65 4

Run parameter sweep for free stream velocity:

python run.py -p u_infty 0.2 2.1 0.2

Viewing walls

Open config/walls.xyz in ParaView using the "Auto Detect Format" and "Multi Grid" options only.

To visualize the turbine geometry, download and rotate the STL file with ./scripts/stl.sh, then open ./figures/turbine-y-up.stl in ParaView.

Acknowledgements

Original configuration files (added in e42f3ad3) from Andrew Murphy Wilson (@awilmurph). The script for creating the wall mesh (./scripts/makewalls.py) was based on one by Phillip Chiu (@whophil), who implemented the wall panels in CACTUS.

Foil data

File name	Reference
NACA_0021_Sheldahl.dat	Sheldahl, R. and Klimas, P. (1981) "Aerodynamic Characteristics of Seven Symmetrical Airfoil Sections Through 180-Degrees Angle of Attack for Use in Aerodynamic Analysis of Vertical Axis Wind Turbines".
NACA_0021_Gregorek.csv	Static data from Gregorek, G. M.; Hoffman, M. J. and Berchak, M. J. (1989) "Steady state and oscillatory aerodynamic characteristics of a NACA 0021 airfoil". Reynolds number values are divided by 1 million.
NACA_0021_Jacobs*.csv	Lift coefficient data manually digitized from Jacobs (1932) "The aerodynamic characteristics of eight very thick airfoils from tests in the variable density wind tunnel".
NACA_0018_Jacobs*	Data from Jacobs and Sherman (1937), tabulated in Miley (1982) "A catalog of low Reynolds number airfoil data for wind turbine applications".
NACA_0021_XFOIL*	Generated by Andrew Wilson.

How to cite

This work can be cited via DOI thanks to Zenodo:

License

Code licensed under the MIT license. See LICENSE for details. All other materials licensed under a Creative Commons Attribution 4.0 International License.