Next Generation Helicopter Vibration Suppression
In May of 2011, LORD Corporation's design and test efforts on a vibration control test rig were presented at the American Helicopter Society (AHS), by Russ Altieri from LORD and Mikel Brigley of Sikorsky Aircraft Corporation.
A Hub Mounted Vibration Suppressor (HMVS) working in tandem with a fuselage based Active Vibration Control system (AVC) achieved a new vibration control system performance. Ground tests were performed at a LORD test facility on a CH-3 fuselage. The anti-vibration system incorporated into this rig is designed to completely suppress vibratory motions at the main rotor gearbox, thus precluding fuselage vibration due to main rotor vibratory excitation. Tests were conducted to simulate various static and dynamic in-flight loadings and main rotor shaft speed conditions. The test results indicate that the system successfully suppressed virtually all of the vibratory loads applied to the test main rotor hub, yielding very low fuselage vibrations. Testing was performed under a cooperative Technology Investment Agreement (TIA) between Sikorsky Aircraft and the Army Aviation Applied Technology Directorate (AATD).
The concept of a new vibration control system that is capable of nullifying the 4/rev vibratory loads at the main rotor gear box before they can propagate into the fuselage was demonstrated. Furthermore, this testing indicates that systems incorporating this approach can yield virtually zero vibration levels throughout the entire fuselage. A flight test is planned to further advance this technology in 2012.