Active load control of an articulated composite rotor blade via dual trailing edge flaps

Jun Sik Kim, Edward C. Smith, K. W. Wang

Research output: Contribution to journalConference articlepeer-review

9 Scopus citations


A new active load control method for blade bending moment reduction is introduced and evaluated via simulation. The concept involves straightening the blade by introducing dual trailing edge flaps in a conventional articulated rotor blade. An aeroelastic model is developed for a helicopter composite rotor with trailing edge flaps, and the rotor blade airloads are calculated using quasi-steady blade element aerodynamics. Classical incompressible theory is employed to predict the incremental trailing edge flap airloads. The objective function, which includes vibratory hub loads, bending moment harmonics and active flap control inputs, is minimized by an integrated optimal control/optimization process. A numerical simulation has been performed for the steady-state forward flight of advance ratio 0.35. It is demonstrated that through straightening the rotor blade, which mimics the behavior of a rigid blade, both the bending moments and vibratory hub loads can be significantly reduced. The proposed active load control method with 1/rev control input can reduce the flapwise bending moment by 32% and the vibratory hub loads by 57%, simultaneously, without a significant change of trim condition. Hybrid design yields a 25% reduction of the required flap deflection when compared to the pure active control.

Original languageEnglish (US)
Pages (from-to)1329-1340
Number of pages12
JournalCollection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
StatePublished - 2003
Event44th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference - Norfolk, VA, United States
Duration: Apr 7 2003Apr 10 2003

All Science Journal Classification (ASJC) codes

  • Architecture
  • General Materials Science
  • Aerospace Engineering
  • Mechanics of Materials
  • Mechanical Engineering


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