Transonic Performance of Jet Flaps on an Advanced Fighter Configuration.
Abstract
Wind tunnel tests were carried out in the NASA (Ames) 11 x 11 ft Unitary Wind tunnel to determine the effectivity of jet flaps on an advanced fighter configuration to improve the transonic high lift performance. The Mach number range was 0.40 - 0.95; the Reynolds number range 2.5 - 7.0 x 6,000,000 ft; and the angle of attack range was approximately 0 to 25 degrees. Wing sweeps of 26 degrees and 45 degrees; jet flap angles of 60 degrees and 80 degrees; and jet momentum coefficients C sub mu in the range 0 to 0.039 were tested. Balance measurements, extensive pressure distributions, and wing root bending moment and wing tip accelerometer measurements were obtained. The results in general indicated that sectional jet flap lift augmentations along the span comparable to the planar results can be achieved, so long as three dimensional lateral erosive effects, primarily from the inboard glove region, can be avoided. Overall lift coefficient increments due to the jet flap were found to be less than the planar results, but there was a substantial improvement of the drag polars at the large lifts. The jet flap lift augmentation was found to be sustained to the highest incidence tested, suggesting the potential use of the jet flap for direct lift control or lateral control. Particularly effective was the partial span jet flap where a significant carryover to the nonblown region of the wing was observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1973
- Accession Number
- AD0913798
Entities
People
- David Benepe
- Hideo Yoshihara
- Perry Whidden
Organizations
- General Dynamics