Aeroservoelastic Response of Nonlinear Wind Tunnel Model to Non-Uniform Gust Field

A pre-test numerical aeroservoelastic simulation of the response of a wind-tunnel model to gust excitation is presented. The model includes nonlinear actuators that have internal saturation elements and their dynamics are affected by the output hinge moments. A direct-force feedback and fictitious masses are used to facilitate such actuators in the response analysis. The Increased-Order Modeling approach and the associated Dynresp code are employed to perform the response calculations using combined frequency- and time-domain solutions. A CFD-based non-homogeneous gust field is used to excite the numerical simulation. The model is supported by a simple spring-damper system that yields stable rigid-body pitch dynamics of frequency well below that of the structural response. A PID controller that reads the CG vertical accelerometer only and commands the two ailerons equally is applied. The controller reduces the maximal wing-root bending moment in response to a typical 1-cos gust excitation by 24%.