The results of a computational study of the effects of various design parameters on tiltrotor whirl flutter characteristics are reported. First, the influence of parameter variations are considered individually, including design variables such as rotor flexibility distribution inboard/outboard of the pitch bearing, which have not been previously addressed in the literature. Parametric studies are followed by the use of formal design optimization techniques. When tight parameter constraints are enforced during optimization, the resulting design is consistent with the trends observed in the parametric studies. The parameters most influential in increasing flutter speed are: pitch-flap and pitch-lag couplings, and distribution of flap flexibility inboard/outboard of the pitch bearing. When constraints on the design variables are relaxed, the resulting optimal designs differ from expectations based on parametric study trends. Of particular interest is the reduced sensitivity to the delta(Ind 3 ) angle (pitch-gimbal coupling). With large negative delta(Ind 3 )values permissible, the design of tiltrotors with four or more blades may be feasible.
Design optimization for improved tiltrotor whirl flutter stability
Entwurfsoptimierung eines Kipprotors mit verbesserter Wirbel-Flatter-Stabilität
Journal of the American Helicopter Society ; 52 , 2 ; 79-89
2007
11 Seiten, 21 Bilder, 3 Tabellen, 26 Quellen
Aufsatz (Zeitschrift)
Englisch
Design Optimization for Improved Tiltrotor Whirl Flutter Stability
Online Contents | 2007
|Design Optimization for Soft-Inplane Tiltrotor Whirl Flutter Stability Improvement
British Library Conference Proceedings | 2007
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