A wind tunnel model test program was conducted to investigate the effectiveness of a focused isolation system in reducing the transmission of rotor-induced vibratory loads for a four-bladed hingeless rotor. The model consisted of a four-bladed hingeless rotor and a simulated transmission mounted on a focal isolation system having pitch and roll degrees of freedom. Analytical considerations indicate that there is no single focus which will simultaneously isolate both hub moments and inplane loads. For the four-bladed hingeless rotor with large vibratory hub moments, the optimum focus lies close to the combined rotor/transmission center of gravity. Model test results indicated two configurations with reasonable moment isolation. One was an upward focus near the combined rotor/transmission center of gravity. The second, which had an effective downward focus, produced high lateral and longitudinal loads. (Author)
Evaluation of Pylon Focusing for Reduced Helicopter Vibration
1979
95 pages
Report
Keine Angabe
Englisch
Aircraft , Helicopter rotors , Transmissions(Mechanical) , Vibration isolators , Struts , Hubs , Rotor blades(Rotary wings) , Aerodynamic loading , Vibration , Focusing , Center of gravity , Moments , Wind tunnel tests , Degrees of freedom , Pitch(Motion) , Roll , Bending moments , Structural response
HIGH STIFFNESS ("RIGID") HELICOPTER PYLON VIBRATION ISOLATION SYSTEMS
British Library Conference Proceedings | 2003
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