OpenFAST simulations for the NREL 5MW turbine

This repository contains the data files and code to run simple simulations of the NREL 5MW wind turbine using the OpenFAST simulation code.

Simulations

Simulations are defined in subfolders of simulations/. You can add more variations by adding addition .fst files within an existing subfolder, or by creating a new subfolder. More details below.

Baseline turbulent wind simulations

baseline at 12 m/s and baseline_8ms at 8 m/s

Alternative controller

To demonstrate an [arbitrary] change to the controller code, the controller_tweaked simulations are the same as the baseline simulations but they use the DISCON_tweaked controller.

Linearised models

linearised
lineared_fixed_rotor_speed -- how is this different from linearised/trim_none_no_gen_dof? I think it's not used?
linearised_trim_torque -- think this is not used`

Sinusoidal wind input

Steady wind

steady_wind
steady_wind_simplified has only the generator speed and 1 tower mode active

Analysis / results

The following Jupyter notebooks are in the analysis/ folder.

Results - compare turbulent to linearisation

Compares the results of

baseline_8ms/5MW_Land_DLL_WTurb_fixedspeed_toweronly
linearised/trim_none_no_gen_dof

Results - compare sinusoidal to linearisation

Compares the results of

sinusoidal_just_tower_no_gen_dof
sinusoidal_just_tower
(sinusoidal_no_tower_no_gen_dof -- TODO this doesn't exist yet)
linearised/trim_none_equilib
linearised/trim_none_no_gen_dof
linearised/trim_none_no_gen_dof_no_tower

This shows for a simple condition with just 1 or 2 degrees of freedom how the linearised state-space model compares to the non-linear time-domain solution with sinusoidal uniform wind input.

Effect of neglecting blade dynamics

Comparison between baseline_8ms/5MW_Land_DLL_WTurb and baseline_8ms/5MW_Land_DLL_WTurb_nobladedof

(just as an example of how the results differ if we arbitrarily simplify the model by neglecting the flexibility of the blades)

Results - steady state

Plots the results of steady_wind simulations

Compare tweaked controller to original

Plots the results of the baseline simulations with the original controller against equivalent simulations controller_tweaked with the DISCON_tweaked controller.

Installation

Use conda to install the Python packages to set up and analyse the simulations. All the necessary packages should (...) be listed in the environment.yml conda file, so all that should be necessary is to run in this folder:

conda env create
conda activate openfast_env

Each time you open a new terminal, you need to re-run the conda activate openfast_env command to activate that conda environment.

Installing OpenFAST on Mac OS

On Mac OS, the OpenFAST wind turbine simulation software can also be installed with conda. With your openfast_env conda environment activated, run

conda install -c conda-forge 'openfast==3.0.*'

Installing OpenFAST on Windows

On Windows, OpenFAST is not available via conda so must be downloaded directly from the GitHub releases page. Download the following files and save them in the same directory as this project.

openfast_x64.exe, saved as openfast.exe
TurbSim_x64.exe, saved as turbsim.exe

Running simulations

Simulations are managed using doit to keep track of which simulations need to be re-run when input parameters change, and to create sets of simulations (with different wind speeds, or different realisations of a turbulent wind field).

Basically, each subfolder of simulations/ is copied into runs/... including any necessary variations. Then OpenFAST is run for each generated folder in runs/. The generation of variations is defined somewhat messily in the function task_prepare_fast_input within dodo.py.

Other doit tasks take care of:

Generating turbulent wind field files based on the input parameters in the wind/ folder
Compiling the controller code into a DLL file for use within the simulations

You can run all out-of-date simulations using doit run -v2 -n5. Here -v2 tells doit to print all output to the console (you can skip this if you want to see less detail). -n5 tells doit to run up to 5 tasks in parallel; again you can skip this.

You can list all the available tasks by running doit list, and then see subtasks by running doit info TASK. For example one of the subtasks listed by doit info openfast is openfast:steady_wind:ws4.0:5MW_Land_DLL_Steady which runs the simulation defined in simulations/steady_wind/5MW_Land_DLL_Steady.fst, placing the output in runs/steady_wind/ws4.0/5MW_Land_DLL_Steady.out.

Setup for compilation (e.g. of controller)

Linux (including WSL)

Install required tools -- run this in your terminal (Ubuntu):

sudo apt install git cmake gfortran g++

Windows

Install Visual Studio Community 2019 from https://my.visualstudio.com/Downloads?q=visual%20studio%202019&wt.mc_id=o~msft~vscom~older-downloads
- In the installer, select the "Desktop development with C++" option in the Workloads tab
Download and install the Intel Fortran Compiler from https://www.intel.com/content/www/us/en/developer/articles/tool/oneapi-standalone-components.html#fortran

hzzz123 / OpenFAST-NREL-5MW