Computer-Aided Engineering Tools

WT_Perf uses blade-element momentum theory to predict the performance of wind turbines.  It is a descendent of the PROP code originally developed by Oregon State University.  Over the intervening years, many people from many organizations put their marks on the code.  More recently, the staff at the NWTC rewrote the program, modernized it, and added new functionality and algorithms.

We have not created a theory manual explicitly for WT_Perf.  However, as WT_Perf is a descendent of the PROP code with minor theory changes and is somewhat similar to AeroDyn, there are a few documents you might find useful:

• WilsonLissaman_AppAeroOfWindPwrMach_1974.pdf
  Applied Aerodynamics of Wind Power Machines
  Robert E. Wilson
  Peter B. S. Lissaman
  Oregon State University
  May 1974

• HibbsRadkey_BEM_Theory.pdf
  Small Wind Energy Conversion Systems (SWECS) Rotor Performance Model Comparison Study (UNPUBLISHED DRAFT)
  B. Hibbs
  R.L. Radkey
  Aerovironment, Inc.
  November 1981

• AIAA-2011-150-703
  An Investigation of WT_Perf Convergence Issues
  David C. Maniaci
  The Pennsylvania State University
  January 2011

• NREL/CP-500-36881
  AeroDyn Theory Manual
  Pat J. Moriarty
  NREL-NWTC
  A. Craig Hansen
  Windward Engineering
  January 2005

• NREL/CP-500-36834
  A New Empirical Relationship between Thrust Coefficient and Induction Factor for the Turbulent Windmill State
  Marshall L. Buhl Jr.
  NREL-NWTC
  August 2005

You may download the following files from our server:

• WT_Perf Change Log (3.05.00a-adp, 31 KB, 09-November-2012)

  This is a list of changes made to the code.  Look at this text file to see if we've made worthwhile changes since you received your previous version of the WT_Perf.

• WT_Perf User's Guide (3.05.00a-adp, 574 KB, 09-November-2012)

  This is a brief guide that explains how to use WT_Perf. This includes information on what the options are within the input file as well as some information on how the program works.

• WT_Perf Archive for Windows ( 3.0 MB) (3.05.00a-adp, 3.0 MB, 13-November-2012)

  This is a self-extracting archive of WT_Perf.  Simply execute it in an appropriate directory to extract the files.  It contains the change log, the source code, and some archive/web support files.

• WT_Perf Archive (tar.gz 2.5 MB) (3.05.00a-adp, 2.5 MB, 13-November-2012)

  This is a compressed archive of WT_Perf.  It contains the same files as WT_Perf Archive for Windows, but is stored in tar.gz format for non-Windows users.

• NWTC Subroutine Library

  If you want to make changes to WT_Perf and/or recompile the code, you will need to download the NWTC Subroutine Library v1.05.00 archive of general-use routines and modules.

You may download the following older files from our server:

• Old WT_Perf Archive (1.5 MB) (3.10, 1.5 MB, 02-July-2004)
• Old WT_Perf Archive (2.5 MB) (3.04.00d-mlb, 2.5 MB, 21-June-2011)
• Old WT_Perf Guide (97 KB) (Dec 2004, 97 KB, 17-December-2004)

If you want to refer to the WT_Perf in a report, here is a reference you can use:

NWTC Design Codes (WT_Perf by Andrew Platt).  http://wind.nrel.gov/designcodes/simulators/wtperf/.  Last modified 26-November-2012; accessed 26-November-2012.