Hot-wire surveys in the vortex wake downstream of a three-percent fighter aircraft model at high angles of attack

• Main Author: Frink, William D., Jr.
• Other Authors: Hebbar, Sheshagiri K.
• Published: Monterey, California: Naval Postgraduate School 2013
• Online Access: http://hdl.handle.net/10945/27586

Approved for public release; distribution is unlimited. === A low-speed wind tunnel investigation was conducted to examine the vortex wake downstream of a three-percent scale model of the YF-17 lightweight fighter prototype at high angles of attack. The study was in support of NASA ames Research Center's wind tunnel investigation of a full scale FA-18 as part of NASA's High Alpha Technology Program. Smoke flow visualization was used to locate the downstream vortex wake. Hot-wire surveys were taken through the vortex at two stations; one directly aft of the model and the other at a station three model lengths downstream of the model. The effect of adding a fence to the leading edge extension (LEX) was studied. Power spectra from the hot-wire were recorded for the survey station directly aft of the model. Results show that: peak turbulent fluctuation at this station occurred at 25 deg angle of attack; lateral turbulent fluctuation greatly diminished at the far downstream station; and the addition of the LEX fence shifted energy content of turbulence toward higher frequencies.