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Aeroelastic stability of wind turbine blade/aileron systemsAeroelastic stability analyses have been performed for the MOD-5A blade/aileron system. Various configurations having different aileron torsional stiffness, mass unbalance, and control system damping have been investigated. The analysis was conducted using a code recently developed by the General Electric Company - AILSTAB. The code extracts eigenvalues for a three degree of freedom system, consisting of: (1) a blade flapwise mode; (2) a blade torsional mode; and (3) an aileron torsional mode. Mode shapes are supplied as input and the aileron can be specified over an arbitrary length of the blade span. Quasi-steady aerodynamic strip theory is used to compute aerodynamic derivatives of the wing-aileron combination as a function of spanwise position. Equations of motion are summarized herein. The program provides rotating blade stability boundaries for torsional divergence, classical flutter (bending/torsion) and wing/aileron flutter. It has been checked out against fixed-wing results published by Theodorsen and Garrick. The MOD-5A system is stable with respect to divergence and classical flutter for all practical rotor speeds. Aileron torsional stiffness must exceed a minimum critical value to prevent aileron flutter. The nominal control system stiffness greatly exceeds this minimum during normal operation. The basic system, however, is unstable for the case of a free (or floating) aileron. The instability can be removed either by the addition of torsional damping or mass-balancing the ailerons. The MOD-5A design was performed by the General Electric Company, Advanced Energy Program Department under Contract DEN3-153 with NASA Lewis Research Center and sponsored by the Department of Energy.
Document ID
19950021560
Acquisition Source
Legacy CDMS
Document Type
Other
Authors
Strain, J. C.
(General Electric Co. Philadelphia, PA, United States)
Mirandy, L.
(General Electric Co. Schenectady, NY., United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1995
Publication Information
Publication: DASCON Engineering, Collected Papers on Wind Turbine Technology
Subject Category
Aerodynamics
Accession Number
95N27981
Funding Number(s)
CONTRACT_GRANT: DEN3-153
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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