Effects of dual synthetic jets on longitudinal aerodynamic characteristics of a flying wing layout

A novel method of flight control based on dual synthetic jets (DSJ) is proposed and applied to a large-sweep flying wing aircraft with a hybrid flow mode of leading-edge vortex (LEV) and spanwise separation. An array of dual synthetic jet actuators (DSJAs) is placed along the leading edge to explore its aerodynamic control characteristics and control mechanism. The comparison with synthetic jets (SJ) is implemented to show the differences. Results show that DSJ could delay stalling angle of 6 degrees and promote Cl with greater increments at large attack of angles (AOAs). At AOA of 36 degrees, there was an obvious increase of 23.12% in Cl. Cd decreases at small AOAs, while augments sharply when AOA is larger than 26 degrees. Nose -up moment could be improved. Above features indicate that leading-edge DSJ is not only a nice method of lift enhancement but also an efficient way of flight control. In the fuselage section, DSJ has functions of strengthening LEV, delaying the LEV breakdown and even regenerating LEV at large AOAs, which enhances the bleeding and improves the ability of resisting the reverse pressure gradient, thus totally suppressing the separation and forming the larger leading-edge suction. In the wing section, DSJ acts as a "LEV generator". Reconstructed LEV could interact with the initial spanwise separation, emerging a hybrid flow mode of "streamers" and "rollers", in which flow energy could be augmented and separation is partly suppressed. The comparison with SJ supports that the larger leading-edge suction and stronger LEV could be achieved by DSJ, which generate greater increments of Cl and Cm. Maximum Cl increments achieved by DSJ and SJ are respectively 23.12% and 16.91% of Cl without control, meaning DSJ has the higher applying potential in flight control with the same energy consumption. (c) 2022 Elsevier Masson SAS. All rights reserved.