Panel Flutter

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Suppression of Nonlinear Panel Flutter at
Supersonic speed
Myounghee Kim. Department of Aerospace
Engineering Old Dominion University, Norfolk, VA
23529
3rd KSEA YGTLC New York, 5-7 January 2007
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Objectives

• Develop nonlinear panel flutter equation using
  finite element Modal method.
• Transfer equations of motion to Aeroelastic Modal
  Coordinates (AEMs).
• Place the Piezoelectric actuators at the optimal
  locations based on NFCG method.
• Apply LQR controllers to suppress Nonlinear panel
  flutter of a beam and a isotropic plate based on
  2 AEMs.

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What is Panel Flutter ?

• Self-Excited Oscillations of an external panel of
  high speed vehicles with airflow on one-side of
  the panel only

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Motivation of Modes

Eigenvalues ? versus dynamic pressure ? for a
simply supported isotropic square plate (24x3
mesh half-plate, 72 BFS elements, 288 DOF, 6
natural modes)
From Guo and Mei, AIAA J 2004
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Motivation of Modes

• The LCO deflection is very close to first AE
  mode shape
• 2AEMs is converged much faster than 6NMs

LCO (Limited cycle Oscillation)
Deflection Mode shape
Wmax/h Modal Participation, Modal Participation, Modal Participation, Modal Participation, Modal Participation, Modal Participation, Modal Participation,
Wmax/h Modes q1 q2 q3 q4 q5 q6
0.51 AEM 63.93 34.83 0.91 0.21 0.08 0.03
0.51 NM 59.86 30.50 5.96 2.28 0.88 0.46
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