Twin Jets Screech Suppression Concepts Tested for 4.7% Axisymmetric and Two-Dimensional Nozzle Configurations.

摘要

The sonic fatigue of nozzle flaps on F-15 and B-1 aircraft has demanded an increase in aeroacoustics research. A 4.7% scale, cold, static test was conducted at the Wright Research and Development Center (WRDC) to investigate noise suppression concepts on F-15 axisymmetric and two-dimensional nozzle configurations. These concepts included lateral spacing, secondary air jets, and tab suppression. Nozzle orientation parametrics included nozzle canting and pitch deflection. Design guideline charts are presented showing screech amplitude variation for each suppression and orientation concept. Keywords: Aerodynamic noise, Exhaust nozzles, Jet engine noise. (emk)