Helicopter rotor systems are constructed to tight tolerances, but slight manufacturing variations in blades and rotor head components cause lift and dynamic response to vary among blades. The rotor adjustments typically used to trim and optimize 1/rev vibration are blade pitch rod length adjustment, blade trailing edge trim tab angle adjustment, and rotor weight balance adjustment. These adjustments are manually implemented in a relatively inefficient way that is time consuming and sometimes prone to error. A system is desired that would enable the results of a computerized diagnostic algorithm to be applied to a rotor adjustment system in an automated way so changes are made in a quick, efficient, repeatable, and error free manner. Mide, with assistance from Sikorsky Aircraft, under contract from AATD, has advanced active trim tab technology for a H-60 BLACK HAWK blade using shape memory alloys.1 The performance of the SMA tab was evaluated on a scaled rotor test stand. The test results indicate that an active SMA trim tab can operate on a helicopter blade. The centrifugal loads of the rotor did not adversely affect the operation of the SMA tab. The deflection of the SMA tab was sufficient to induce pitch moment changes required for main rotor 1/rev vibration tuning and blade tracking.
Active trim tab for rotor track and balance
2008
14 Seiten, 7 Quellen
Conference paper
English
Active Trim Tab for Rotor Track and Balance
British Library Conference Proceedings | 2008
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