Performance characteristics of nonaxisymmetric nozzles installed on the F-18 aircraft

Abstract

ideal thrust Abstract Fi FS fuselage station, in The Langley Research Center has conducted an exoerimental D r m r a m an a model of the F-18 air-. -M Mach number plane to determine the performance of nonaxisymmetric nozzles relative to the aircraft's NPR Nozzle pressure ratio c( baseline axisymmetric nozzle. The performance of a single expansion ramp (ADEN) and twodimensional convergent-divergent (2-D C-D) nozzle were compared to the baseline axisymmetric nozzles. angle of attack, deg 6 measured effective static turning The effects of vectoring and reversing were also studied. Performance of a modified YF-17 airplane with the ADEN nozzle was also estimated. The angle, deg results of this investigation indicate that nonaxisymmetric nozzles can be installed on a twin engine fighter airplane with equal o r better performance than axisymmetric nozzles. axisymmetric nozzles also offer potential for innovative and improved aircraft maneuver through thrust vectoring and reversing. The YF-17/ADEN flown as a technology demonstrator would 4have reduced performance compared to an unmodified YF-17. However, on an equal aircraft weight basis, performance would essentially be equivalent. This study also showed that the YF-17 can serve as a testbed to validate nonaxisymmetric nozzle technology.The "on- Symbols