NWTC Design Codes - General Questions

Hello everybody.
As a newcomer to this forum and a learner in wind energy industry I have several questions (very general) regarding the design codes.

As for my questions:

My target is to analyze a 500kW wind turbine. I have airfoil data ready (*.dat). I have main metrics of the turbine ready (hub height, rotor diameter etc.)

  1. I am planning to use AeroDyn and FAST together. FAST is compiled and needs an .ipt file to operate. AeroDyn is in source code format. Shall I have to compile it? Or is it included in FAST code?
  2. Is there a tutorial explaining the methodology. (preparing the data files (.dat, .wnd, .bts .fts), running the code, evaluating the results?)
  3. Perhaps it would be a good idea to wrap the code into languages like C++ or java for ease of usage.
  4. Load cases will be generated by IECWind for IEC 61400-1:2005 compatibility. I think this is OK?
  5. I have seen Mr.Jonkman’s Modeling Workshop documents I will read them, any beginner’s documentation are very welcome.

Thank you.

Devrim Ersanli

Dear Devrim,

Here are my answers to your questions:

  1. The AeroDyn and FAST source code are compiled together into a single executable (i.e., the FAST.exe). FAST calls AeroDyn to calculate the aerodynamic forces at runtime.

2/5. No such step-by-step instructions exists. Several years ago Marshall Buhl summarized his analysis approach, which you can find here: wind.nrel.gov/designcodes/advice.html. While some of the information is out-of-date, there is still some good advice to be found there. The NREL Wind Turbine Modeling workshop material is currently our best source for background information and a tutorial on FAST with AeroDyn and HydroDyn: http://forums.nrel.gov/t/nrel-wind-turbine-modeling-workshop-march-2-2012/463/1.

3/4. Most serious users of FAST have developed scripts for their own purposes. We have a few scripts available on the design codes website:

*RunIEC: Runs IECWind, FAST, & Crunch for IEC discrete load cases
*RunNTM: Runs TurbSim, FAST, & Crunch for multiple turbulence cases
*CondorNTM: Same as RunNTM, but uses Condor

All of these scripts are written in Perl; you must know a little Perl to use them. No further development of these scripts is planned.

We also have an in-house script also called RunIEC that:
*Combines features from all three of the above scripts
*Is tailored to IEC-style load cases
*Runs jobs serially, on Condor pool, or on HPC (multi-processor server)
*Currently requires significant customization to use

We are in the process of reworking RunIEC to make some improvements and to make it is user friendly; when this is done, we plan to write a user manual for it and distribute it later this year.

Before then, it is probably easiest to start with the scripts currently available on the website and customize them for your own use.

I hope that helps.

Best regards,


With regards to your message above do you have an expected release date for the updated RunIEC (ie newer than V2)?


Nic Strum


We have a newer version of RunIEC that we use internally. Although it is a much-better script now than it was before, I would not feel comfortable releasing it into the wild. It is also still highly tailored to our computing environment. I have started documentation that tells people inside our network how to use it and do a loads analysis, but I’ve been distracted by modifying code we need for our internal use and this has not been worked on in months. Once that is done, I would have to convert that into a user’s guide and go throught the (lengthly) publication process.

We have so many things we need to work on and the top priorities are things we need to meet our own milestones. I would love to tell you this will be done in the next few months, but I fear my promise would be broken.