Structural Control of an Aerodynamically-Adaptive Flexible Wing using Distributed Bleed Actuation.

Variable aerodynamic loads that are regulated by controlled quasi-static and transitory interactions of distributed bleed actuation with the cross flow over a flexible 3-D wing model are used to alter its structural and aeroelastic characteristics in wind tunnel experiments. The bleed is driven through arrays of ports on the pressure and suction surfaces by the inherent pressure differences in flight and is regulated using active louvers. The effects of bleed-induced time-dependent changes in the aerodynamic forces and moments are explored using direct load measurements and surface motion analysis coupled with high-speed stereo PIV in a streamwise-normal plane in the near wake. These measurements enable assessment of the spanwise sectional lift distribution over the wing reveal using concentrations of streamwise vorticity. The present investigations demonstrate how spanwise-segmented bleed actuation can excite cross stream oscillations of the wing and independently mitigate these oscillations using the measured tip velocity. Aerodynamic/structural constitutive, multiscale analysis coupled with time dependent distributions of the aerodynamic loads assesses the induced changes in the apparent structural properties of the wing.