YawDyn is a software package for use by designers of horizontal-axis wind turbines. YawDyn must be linked with the AeroDyn aerodynamics package to create an executable for dynamics analysis of constant rpm rotors with two or more blades and a teetering or rigid hub.

The structural dynamics model contained in YawDyn is extremely simple, but useful for analyzing preliminary designs and assessing aerodynamic response.

The YawDyn executable provided was created with the latest AeroDyn code available at the time of the release of the current YawDyn version. Users should check if there is a newer version of AeroDyn to be sure the executable they run is up to date.

Versions of YawDyn and AeroDyn that are v12 or greater do not use input files that are compatible with earlier versions of YawDyn. We have provided a conversion program called Conv_IPT that will convert a YawDyn v11 input file to a YawDyn v12 input file and an AeroDyn v12 input file.

This program and downloadable user's guide assume the user is an experienced wind turbine aerodynamics and dynamics analyst. Questions about this software should be directed to Windward Engineering.

You may download the following files from our server:

• YawDyn Change Log (v12.16, 4 KB, 19-February-2004)

  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 YawDyn.

• YawDyn User's Guide (v12.16, 274 KB, 25-April-2003)

  This is the YawDyn User's Guide.  Please refer to it when trying to understand how the program works.

• YawDyn Archive (v12.16, 2.9 MB, 18-February-2005)

  This is a self-extracting archive of YawDyn.  It contains the YawDyn executable file, sample input files, installation-verification test procedure, change log, and user's guide.  It runs on all 32-bit Windows® platforms.  We compiled the source code with Intel Visual Fortran® w_fc_pc_8.0.050_pe052.1 and linked the resulting object files with AeroDyn v12.57.

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

NWTC Design Codes (YawDyn by Dr. David J. Laino).  http://wind.nrel.gov/designcodes/simulators/yawdyn/.  Last modified 26-May-2005; accessed 26-May-2005.