Aeroservoelastic Test of the Subsonic Ultra-Green Aircraft Research Truss-Braced Wing Model

The Subsonic Ultra Green Aircraft Research Truss-Braced Wing aeroservoelastic wind-tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel. The primary goals of the test were to identify the open-loop flutter boundary and then demonstrate flutter suppression. A secondary goal was to demonstrate gust load alleviation. Open-loop flutter and limit cycle oscillation onset boundaries were identified for a range of Mach numbers and various angles of attack. Two sets of control laws were designed for the model, and both sets of control laws were successful in suppressing flutter. Control laws optimized for gust load alleviation were not designed; however, the flutter suppression control laws were assessed using the Transonic Dynamics Tunnnel airstream oscillation system. This paper describes the experimental apparatus, procedures, and results of the truss-braced wing wind-tunnel model test. Acquired system identification data used to generate aeroservoelastic models are also discussed.