The Natural Excitation Technique (NExT) for modal parameter extraction from operating wind turbines

Technical Report · Mon Feb 01 00:00:00 EST 1993

OSTI ID:10139203

James, III, G H; Carne, T G; Lauffer, J P

The Natural Excitation Technique (NExT) is a method of modal testing that allows structures to be tested in their ambient environments. This report is a compilation of developments and results since 1990, and contains a new theoretical derivation of NExT, as well as a verification using analytically generated data. In addition, we compare results from NExT with conventional modal testing for a parked, vertical-axis wind turbine, and, for a rotating turbine, NExT is used to calculate the model parameters as functions of the rotation speed, since substantial damping is derived from the aeroelastic interactions during operation. Finally, we compare experimental results calculated using NExT with analytical predictions of damping using aeroelastic theory.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 10139203
• Report Number(s): SAND-92-1666; ON: DE93010611
• Resource Relation: Other Information: PBD: Feb 1993
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
VERTICAL AXIS TURBINES
TURBINE BLADES
EQUATIONS OF MOTION
AERODYNAMICS
ROTATION
TESTING
OSCILLATIONS
DAMPING
RESPONSE FUNCTIONS
MATHEMATICAL MODELS
ANALYTICAL SOLUTION
WIND
170602
990200
TURBINE DESIGN AND OPERATION
MATHEMATICS AND COMPUTERS