Oscillation of vortex breakdown location and blowing control of time-averaged location

The goal of this research is the control of leading-edge vortex breakdown l ocation utilizing along-the-core blowing near the apex on the leeward surfa ce of sharp-edged, slender, delta wings at high angles of attack. In the S2 Ch subsonic wind tunnel at ONERA Chalais-Meudon, two delta wing models with 70-deg sweep angles and root chords of 950 mm have been configured to coll ect qualitative and quantitative surface and flowfield data. First, an exam ination of the streamwise, time-dependent oscillation of the leading-edge v ortex breakdown locations without active Row control is presented. These re sults further the understanding of the vortex breakdown phenomena and provi de a more precise basis for evaluating the effectiveness of various Row con trol methods. Second, open-loop blowing along one of the vortex cores on th e leeward surface of the delta wing demonstrates the ability to displace do wnstream the controlled, time-averaged, vortex breakdown location by 20% of the root chord.