Study on gust load alleviation control method and mechanism of dual synthetic jets cooperating with deflected rudder

Gusts induce abrupt alterations in freestream velocity, directly resulting in localized aerodynamic load concentrations on the airframe. This study presents a numerical simulation researching on gust load alleviation, based on dual synthetic jets (DSJ) cooperating with mechanical deflected rudder, innovatively combing dual synthetic jets with a deflected rudder, and validating the met hod's ability to against gust disturbances. The result shows that dual synthetic jets combing with a deflected rudder improve the pressure differential between the upper and lower airfoil profiles and reduce the lift coefficient under the disturbance of the gust. The ability of gust load alleviation enhances with increasing dual synthetic jets momentum coefficient. The lift coefficient reduces from 0.444 to 0.005 when the dual synthetic jets momentum coefficient reaches 0.1081. The analysis of flow control mechanisms for lift reduction through the synergistic integration of dual synthetic jets with deflectable rudder demonstrated that dual synthetic jets mitigate the adverse pressure gradient on the lower surface of the rudder by injecting energy into the boundary layer. It compels the original high-speed airflow to deflect upward while periodically expanding the high-speed flow domain on the lower wing surface, thereby enhancing the lift-reduction effectiveness of the deflected rudder. Compared with the synthetic jet, dual synthetic jets have the advantage of less cyclic fluctuations and greater gust alleviation potential. The gust load alleviation efficiency of dual synthetic jets increasing 11.56% when momentum coefficient reaches 0.1081.