Flutterometer: An On-Line Tool to Predict Robust Flutter Margins

Robust eutter margins can be computed for an aeroelastic model with respect to an associated uncertainty descriptionthatdescribes modelingerrors. Anon-lineimplementationtocomputetheserobustmarginsisconsidered. The on-line approach generates uncertainty descriptions at test points and can account for time-varying errors in themodel.A eutterometer isintroduced as an on-linetool toindicateameasure ofdistancetoe utterduringaeight e utter test. Suchatool is formulated based on robust euttermargin analysis. A e ight test of an F/A-18 is simulated todemonstrate theperformance ofthee utterometer.Thistool isclearly more informativethantraditional tracking of dampingtrends and provides accurate information about the true eutter margin throughout the e ight test. The simulation demonstrates characteristics of the eutterometer that could improve eight test efe ciency by increasing safety and reducing eight time for envelope expansion.