Evaluation of Four Advanced Nozzle Concepts for Short Takeoff and Landing Performance

Abstract

Four advanced nozzle concepts were tested on a canard-wing fighter in the Langley 14- by 22-Foot Subsonic Tunnel. The four vectoring-nozzle concepts were (1) an axisymmetric nozzle (AXI), (2) an asymmetric, load-balanced exhaust nozzle (ALBEN), (3) a low aspect ratio, single expansion ramp nozzle (LASERN), and (4) a high aspect ratio, single expansion ramp nozzle (HASERN). The investigation was conducted to determine the most suitable nozzle concept for short takeoff and landing (STOL) performance. The criterion for the best STOL performance was a takeoff ground roll of less than 1000 ft. At approach, the criteria were high lift and sufficient drag to maintain a glide slope of 03 ffi to 06 ffi with enough pitching-moment control from the canards. The test was performed at a dynamic pressure of 45 lb/ft 2 and an angle-of-attack range of 0 ffi to 20 ffi . The nozzle pressure ratio was varied from 1.0 to 4.3 at both dry power and afterburning nozzle configurations with nozzle ..