Passive control of wing/store flutter

Abstract

This paper presents results for a passive flutter suppression approach known as the decoupler pylon. The decoupler pylon dynamically isolates the wing from store pitch inertia effects by means of soft-spring/damper elements assisted by a low-frequency feedback-control system which minimizes static pitch deflections of the store due to maneuvers and changing flight conditions. Wind-tunnel tests and analyses show that this relatively simple pylon suspension system provides substantial increases in flutter speed and reduces the sensitivity of flutter to changes in store inertia and center-of-gravity location. Flutter characteristics of F-16 and YF-17 flutter models equipped with decoupler pylon-mount stores are presented and compared with results obtained on the same model configurations using active flutter suppression systems. These studies show both passive and active concepts to be effective in suppressing wing/store flutter. Also presented are data showing the influence of pylon stiffness nonlinearities on wing/store flutter.