High-Accuracy Simulations of Robust LCO Control Using Synthetic Jet Actuators

In the follow-up study to Ref. [1], we investigate a benchmark case of a robust nonlinear control of gustinduced limit-cycle oscillations (LCO) of an elastically-mounted transitional airfoil using synthetic-jet actuators (SJA) embedded in the airfoil design of a small-size unmanned air vehicle (UAV). The robust controller is particularly advantageous for high levels of uncertainty and nonlinearity present both in the UAV unsteady flight-path environment and the actuator’s response. In the adopted numerical procedure, the actuator is modeled through imposing a fluctuating-velocity boundary condition directly on the airfoil surface for conducting high-accuracy viscous analysis of SJA-based airfoil LCO control governed by the developed robust regulation law. The numerical studies conducted for selected SJA excitation parameters examine the thresholds of the actuator’s control authority to produce the desirable impact.