22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-3.10.1

APPLICATION OF DYNAMIC MANIPULATION ON THE FOREBODY VORTICES OF A SCHEMATIC AIRCRAFT MODEL

R. Lee (1), R. J. Kind (2), E. S. Hanff (2)
(1) Carleton University, Ottawa, Canada; (2) National Research Council, Ottawa, Canada

Keywords: high angle of attack, asymmetric forebody vortices, dynamic manipulation, duty cycle

Wind-tunnel tests have been conducted to further explore the potential of dynamic manipulation of forebody vortices as a means of augmenting directional control of fighter aircraft at high angles of attack. Tests were conducted on an aircraft model having a 65-deg delta wing and a slender, pointed forebody. Two forward-blowing nozzles located near the apex of the forebody served as the means of perturbing the forebody vortices. Blowing is alternated between the two nozzles causing the vortices to switch back and forth between their two asymmetric stable arrangements. It was found that time-average yawing moment can be made to vary linearly between the two extreme values arising from these orientations. The behaviour of other aerodynamic coefficients is also influenced. A peculiar reversal of yawing moment occurs when the blowing momentum exceeds a particular threshold value. Varying the longitudinal and circumferential location of the nozzle exits did not significantly change the control effectiveness.

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