Control of Vortical Structures over a Tailless Chined Forebody-Delta Wing configuration using Synthetic Jets

Modern fighter aircraft designed for low observability commonly combine delta wings with chine forebodies. Both produce strong leading-edge vortices which may interact in ways that can cause non-linear moments and loss of control. Furthermore, it is expected that future fighter aircraft will be tailless to further reduce their radar cross-section, adding to the loss of lateral stability and control. The present research experimentally explores the effectiveness of finite-span synthetic jets on the flowfield around a generic tailless chined forebody-delta wing configuration and the resulting aerodynamic loads. Three different model forebodies with different jet configurations were explored with the objective of affecting the forebody vortices, with the intention of influencing the downstream interaction of these vortices with the wing vortices to, in turn, then delay the onset of vortex breakdown over the wing itself. The mean and unsteady forces and moments are analyzed and compared for the different cases, and Time-Resolved SPIV results are used to explain the effects of the jets on the aerodynamic loads. The data show that an increase in lift, drag and nose-down pitching moment can be achieved using this technique, as well as delaying the occurrence of vortex breakdown and a reduction in the vortices wandering throughout.