"Digital" Tracking Tabs for 1/Rev Vibration Reduction


    A novel approach for providing one-per-rev vibration reduction using collections of discrete active tab devices has recently been completed under an Army-sponsored Phase II SBIR program. Each tab incorporates a patented bistable design that uses SMA wires for transitioning between one of two deflection positions, thereby providing a localized perturbation to the blade aerodynamics at the location of the trailing edge tab. By arranging several such tabs spanwise along the rotorblade, incremental adjustments may be made using these tabs to perform tracking adjustments on the blades, while in flight, avoiding the typical maintenance cycle of fly-measure-land-adjust-repeat for manual blade tracking. The device has been prototyped as part of an SBIR research program, and has been designed so that it may be retrofitted on existing rotor blade systems, thereby providing active in-flight tracking capability to both existing and future rotorcraft.

  • Retrofit design permits adding in-flight tracking to any rotor system.
  • Bistable tab structure only requires current pulse to change position, not to hold it.
  • Discrete tab arrangement limits total current load to one wire at a time.
  • Multiple tabs provides graceful degradation if some tabs are inoperative.
  • Minimal power, weight and form-factor impact on rotor system performance.
  • Rotor system in-flight tracking and vibration reduction.
  • Optimization of spanwise blade aerodynamics with flight condition.
  • Fly-home capability enhancement following blade damage.

Dual SMA-based tracking tabs and associated printed circuit board.

Demonstration testing of "digital" tab tracking effectiveness on Bensen B-8M Gyrocopter.

Click here to view poster

Sponsored in part by Navair Patuxent River.
TPOC: Dean Carico (Navair) (301) 342-1382

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