The Natural Excitation Technique (NExT) for modal parameter extraction from operating wind turbines
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; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6695620
- Report Number(s):
- SAND-92-1666; ON: DE93010611
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
TURBINE BLADES
EQUATIONS OF MOTION
VERTICAL AXIS TURBINES
AERODYNAMICS
ANALYTICAL SOLUTION
DAMPING
DYNAMICS
MATHEMATICAL MODELS
OSCILLATIONS
RESPONSE FUNCTIONS
ROTATION
TESTING
WIND
DIFFERENTIAL EQUATIONS
EQUATIONS
EQUIPMENT
FLUID MECHANICS
FUNCTIONS
MACHINERY
MECHANICS
MOTION
PARTIAL DIFFERENTIAL EQUATIONS
TURBINES
TURBOMACHINERY
WIND TURBINES
170602* - Wind Energy Engineering- Turbine Design & Operation
990200 - Mathematics & Computers