A computational study on tail buffeting suppression by an inflatable bump

Based on self-induction theory, a novel method that uses an inflatable bump to suppress buffeting is proposed and investigated by numerical simulation. A rapidly inflatable bump is packed and attached to the upper surface of a delta wing. When the angle of attack is small, the bump is not inflated and the enhanced vortex lift which mainly depends on vortex intensity is not affected; When severe buffeting begins at a high angle of attack, the bump is inflated, producing a bulge there. The bulge changes the vortex core trajectory, then reduces the unsteady aerodynamic load on tail surface in the separated flow after vortex breakdown, thus achieving the goal of buffeting suppression. Numerical simulation for a model with a delta-wing, twin-tail configuration demonstrates that, the bulge could twist the pathline of vortex core, move vortex breakdown position upstream, closer to the apex at high angles of attack. Moment coefficient about the left tail root is obviously decreased, and corresponding RMS and peak of power spectral density is lessened, too. Of the two bump shapes studied, semisphererical and semicylindrical, the latter delivers a better performance on tail buffeting suppression. In conclusion, an inflatable bump on an appropriate position of the upper surface of the wing is a convenient and reliable way to suppress buffeting.