Computer-Aided Engineering Tools

The following is the abstract of a paper entitled "New Developments for the NWTC's FAST Aeroelastic HAWT Simulator", which was presented at the 23rd ASME / 42nd AIAA Wind Energy Symposium in Reno, NV, 2004:

Discrepancies in response predictions among FAST, ADAMS®, and other industry-accepted wind turbine analysis codes led the National Renewable Energy Laboratory to dedicate significant time and effort to overhauling its FAST aeroelastic horizontal-axis wind turbine simulator.  Included in the overhaul were improvements to the system dynamics models and upgrades in functionality.  Improvements were made to the drivetrain dynamics models, output processing algorithms, tower and blade deflection characterizations, and other models.  New features include an enhanced input/output environment, aeroacoustic noise prediction algorithms, periodic linearization routines for controls design, as well as a preprocessing utility that enables FAST to generate ADAMS datasets of wind turbine models.  In order to verify that the new features and improved models included in the upgraded FAST were correct, verification tests were run against ADAMS.  Comparisons of response predictions between the codes, in general, show excellent agreement.  Regions where the different response predictions do not exactly coalesce are attributable to differences in the modeling techniques.  This work has culminated in an upgraded version of FAST, equipped with more functionality, that predicts more accurate wind turbine responses than previous versions.

Charts of the Comparisons:

The following charts plot the results of FAST v4.31 's certication test.  FAST v4.31 was compiled with AeroDyn v12.56 using Compaq Visual Fortran® v6.6.A.  We generated our MSC.ADAMS datasets using the FAST-to-ADAMS preprocessing cability of FAST.  MSC.ADAMS was run using ADAMS2AD v12.13.

• Test #01 (327 KB, 06-October-2003)

  AWT-27CR2 with many DOFs with fixed yaw error and steady wind. AA plots.

• Test #02 (523 KB, 06-October-2003)

  AWT-27CR2 with many DOFs with startup and shutdown and steady wind. Time plots.

• Test #03 (245 KB, 06-October-2003)

  AWT-27CR2 with many DOFs with free yaw and steady wind. AA plots.

• Test #04 (160 KB, 06-October-2003)

  AWT-27CR2 with many DOFs with free yaw and FF turbulence. PMF plots.

• Test #05 (743 KB, 06-October-2003)

  AWT-27CR2 with many DOFs with startup and shutdown and FF turbulence. Time plots.

• Test #06 (963 KB, 06-October-2003)

  AOC 15/50 with many DOFs with gen start loss of grid and tip-brake shutdown. Time plots.

• Test #07 (222 KB, 06-October-2003)

  AOC 15/50 with many DOFs with free yaw and FF turbulence. PMF plots.

• Test #08 (443 KB, 06-October-2003)

  AOC 15/50 with many DOFs with fixed yaw error and steady wind. AA plots.

• Test #09 (470 KB, 06-October-2003)

  UAE Phase VI (downwind) with many DOFs with free yaw and a steady wind. AA plots.

• Test #10 (780 KB, 06-October-2003)

  UAE Phase VI (upwind) with no DOFs in a ramped wind. Time plots.

• Test #11 (504 KB, 06-October-2003)

  WindPACT 1.5 MW Baseline with many DOFs undergoing a pitch failure. Time plots.

• Test #12 (790 KB, 06-October-2003)

  WindPACT 1.5 MW Baseline with many DOFs with VS and VP and ECD wind. Time plots.

• Test #13 (248 KB, 06-October-2003)

  WindPACT 1.5 MW Baseline with many DOFs with VS and VP and FF turbulence. PMF plots.

• Test #14 (54 KB, 06-October-2003)

  WindPACT 1.5 MW Baseline with many DOFs and system linearization. Column chart.

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

NWTC Design Codes (FAST Verification by Jason Jonkman and Marshall Buhl).  http://wind.nrel.gov/designcodes/simulators/fast/verification/.  Last modified 19-May-2005; accessed 19-May-2005.