Control of Forebody Vortex Orientation to Enhance Departure Recovery of Fighter Aircraft

A combined experimental and analytical study was undertaken to develop active blowing concepts to control the asymmetric orientation of the vortex system emanating from an aircraft forebody at high angles of attack. The objective of the study was to utilize the side force associated with asymmetric vortices, in a controlled manner, to enhance the capability of a fighter to recover from a departure from controlled flight. Results from water tunnel and wind tunnel tests show that a small amount of tangential blowing along the forebody can effectively alter the forebody vortex system and generate large restoring yawing moments. Six degree-of-freedom digital simulation results show this concept can substantially enhance departure recovery characteristics of fighter aircraft having long, slender forebodies.

[1]  K. J. Orlik-Rueckemann,et al.  Aerodynamic aspects of aircraft dynamics at high angles of attack , 1983 .

[2]  David J. Peake,et al.  Three-dimensional interactions and vortical flows with emphasis on high speeds , 1980 .

[3]  O. R. Edwards.  Northrop F-5F shark nose development , 1978 .

[4]  R. Kruse.  Influence of Spin Rate on Side Force of an Axisymmetric Body , 1978 .

[5]  J. Nielsen,et al.  Nonlinearities in missile aerodynamics , 1978 .

[6]  B. L. Hunt,et al.  Pressure and force distributions on a sharp-nosed circular cylinder at large angles of inclination to a uniform subsonic stream , 1976, Journal of Fluid Mechanics.

[7]  G. T. Chapman,et al.  Onset of aerodynamic side forces at zero sideslip on symmetric forebodies at high angles of attack , 1974 .

[8]  H. D. Greer,et al.  Summary of directional divergence characteristics of several high performance aircraft configurations , 1972 .

[9]  J. R. Chambers,et al.  Asymmetric lateral-directional characteristics of pointed bodies of revolution at high angles of attack , 1972 .

[10]  W. H. Clark,et al.  Occurrence and Inhibition of Large Yawing Moments during High-Incidence Flight of Slender Missile Configurations , 1972 .

[11]  L. Schiff,et al.  Results from a new wind-tunnel apparatus for studying coning and spinning motions of bodies of revolution , 1970 .

[12]  J. R. Chambers,et al.  Effects of a pointed nose on spin characteristics of a fighter airplane model including correlation with theoretical calculations , 1970 .

[13]  Walter J. Klinar,et al.  Status of Spin Research for Recent Airplane Designs , 1957 .

[14]  H. Julian Allen,et al.  Characteristics of flow over inclined bodies of revolution , 1951 .

[15]  D. A. Johnson,et al.  Control of forebody vortex orientation to alleviate side forces , 1980 .

[16]  B. L. Hunt,et al.  Prediction of aerodynamic out-of-plane forces on ogive-nosed circular cylinders , 1977 .

[17]  L. B. Schiff,et al.  Aerodynamics of bodies of revolution in coning motion. , 1969 .