Acoustic Suppression Associated with Application of Chevrons to the Trailing Edge of a Supersonic Nozzle

摘要

This paper describes an effort to develop aero-performance efficient technology to suppress noisernfor high-performance military aircraft. Both full-scale and 1/10’th scale model studies are involved in thisrneffort. A flight test has been conducted with the F/A-18 E/F Super Hornet aircraft to obtain baseline highresolutionrnacoustic data with unsuppressed engines. Model scale technologies investigated for acousticrnsuppression have involved study of the use of chevrons and micro-air jet injection applied to the trailingrnnozzle edge region associated with the engine Variable Exhaust Nozzle (VEN) outer flaps. Theserntechniques are known to have a low impact on aero-performance. The paper discusses principle resultsrnfrom flight testing to predict noise and provides preliminary results associated with measured acousticrnmodel data obtained to date with the use of these technologies.