Abstract: A new proportional side forces control technique of slender body at high angle of attack is developed. The effectiveness of the fast-swinging mini-tip strake technique for controlling forebody vortices at high angle of attack is investigated in low-speed wind tunnel experiments on a slender body of revolution with pointed nose configuration. Test results show that, at high angles of attack (30°<α<70°), the new method can make an efficient proportional control of side force with very low input power levels. The instantaneous cross plane flow field on the lee-ward of the forebody is measured by Particle Image Velocimetry(PIV),and the vorticity map and the velocity vector map reveal that the positions of forebody vortices can be manipulated under the control of unsteady micro perturbation. In this way, the yawing moment generated by the forebody vortices provides directional control of high-performance aircraft at high angle of attack.

Key words: forebody vortices control, side forces control, unsteady perturbation, slender body, high angle of attack, flow field measurements, PIV