Active integral twist control for vibration reduction of helicopter rotors during forward flight is investigated in this paper. The twist deformation is obtained using anisotropic piezocomposite actuators embedded in the composite blade construction. An analytical frame-work has been developed to examine integrally-twisted helicopter blades and their aeroelastic behavior during forward flight condition. This is accomplished by modifying an existing multi-body dynamics code, DYMORE, with active material constitutive relations. An Active Twist Rotor (ATR) blade was designed in accordance with this framework. A four-bladed fully-articulated ATR system was built and tested to demonstrate the present concept in forward flight. In parallel, the impact of the integral twist actuation upon the fixed- and rotating-system loads during forward flight is estimated by the proposed analysis. While discrepancies are found in the amplitude of the loads under actuation, the predicted trend of load variation with respect to its control phase correlates well with the experiments. Using the analysis, system identification is performed to estimate the harmonic transfer functions of the ATR system based on linear time-periodic (LTP) approach. A vibration minimizing closed-loop controller can then be designed based on this system identification results.
Helicopter vibration reduction in forward flight using blade integral twist control
2002
10 Seiten, 32 Quellen
Aufsatz (Konferenz)
Englisch
Helicopter Vibration Reduction in Forward Flight using Blade Integral Twist Control
British Library Conference Proceedings | 2002
|Helicopter flight performance improvement by dynamic blade twist
Online Contents | 2016
|