INTERACTION EFFECTS OF A JET FLAP ON A 60 DEGREES DELTA WING AT MACH NUMBER 4, AND COMPARISON WITH TWO-DIMENSIONAL THEORY.
MICHIGAN UNIV ANN ARBOR DEPT OF AERONAUTICAL AND ASTRONAUTICAL ENGINEERING
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Measured normal force increments due to a jet flap issuing perpendicularly from a flat plate wing are presented. Interaction effects caused a magnification of the jet force by a factor of 2.4 to 2.8, when the wing had a turbulent boundary layer. For a laminar boundary layer the jet force magnification ratio varied from 2.5 for the strongest jet tested, to 3.6 for a jet approximately one-tenth as strong. A three-fold change in slot width had very little effect on the interaction. The experimental results are compared with calculations based on a two-dimensional theory which makes use of empirical separation and base pressure data. The calculated interaction forces are larger than those obtained experimentally, but many of the trends are similar. The interaction is predicted to become increasingly more favorable as Mach number increases. At hypersonic speeds it is indicated that a jet flap wing may be competitive in lifting efficiency with a conventional wing at angle of attack, if operation at large lift coefficients is required. Author
- Fluid Mechanics