Pretest Flutter Predictions of the Upcoming Aeroelastic Tiltrotor Wind Tunnel Test

This paper discusses current pretest whirl flutter predictions for the TiltRotor Aeroelastic Stability Testbed (TRAST) using two different multi-body dynamic-based rotorcraft comprehensive analysis codes, CAMRAD II and RCAS. The U.S. Army is developing this new tiltrotor system to validate whirl flutter stability analysis, a critical instability mechanism in this type of aircraft. The TRAST model has been fabricated but has not been tested in the wind tunnel. This paper includes component bench testing results with comparisons to the analysis. The predictions include parametric variations of the pitch spring and the control system geometry that can be conducted on the TRAST model.