Estimation of Active Gust Load Alleviation Performance Considering Flap Actuator Limitations

The mitigation of gust-induced loads requires powerful actuators, which come at the expense of additional mass and cost. This creates a fundamental trade-off: while more capable actuators improve load alleviation, they also increase structural weight and system complexity. To address this challenge, this paper investigates how actuator limitations affect the achievable performance of active gust load alleviation for high-aspect-ratio wings. In order to quantify this dependency, an optimization-based method is developed to estimate the upper bound of achievable load reduction by directly optimizing control surface deflections in response to standardized gust excitations. The method is applied to an aeroelastic simulation model of the Flexop demonstrator aircraft, targeting minimization of the wing root bending moment. To reflect realistic actuator behavior, the optimization includes constraints on deflection, deflection rate, and deflection acceleration, as well as hinge moment and hinge power limitations, which in turn influence weight and cost of the actuation system. Results demonstrate that these actuator constraints strongly affect the attainable load reduction, defining critical trade-off analysis for actuator design. The findings provide valuable insights for early stage assessment of structural load reduction potential and support co-design studies of future aircraft configurations.