Subsonic/supersonic aeropropulsive characteristics of nonaxisymmetric nozzles installed on an F-18 model

Abstract

The Langley Research Center has conducted an experimental program on a model of the F-18 airplane to determine the performance of nonaxisymmetr ic nozzles relative to the aircraft's baseline axisymmetric nozzle at Mach numbers from 0.60 to 2.20. The performance of a two-dimensional convergent-divergent nozzle, a single expansion ramp nozzle (ADEN), and a wedge nozzle were compared to the baseline axisymmetric nozzles. The nonaxisymmetric nozzle did not have these capabilities. The comparisons presented here are for the nozzles in their full forward thrust mode and for the aircraft at zero angle of attack. The results demonstrate that nonaxisymmetric nozzles can be installed on a close-spaced twin-engine fighter with equal or higher performance than the axisymmetric nozzle over the range of Mach numbers tested.