Turbojet engine noise reduction with mixing nozzle-ejector combinations

Willard D. Coles, John A. Mihaloew, Edmund E. Callaghan
naca-tn-4317
Aug 1958


Several noise suppressors consisting of combinations of mixing nozzles and ejectors were tested on two full-scale turbojet engines. Maximum sound pressure level reductions of 12\ decibels and sound power level reductions of 8 decibels were obtained. The ejectors provided 3 to 5 decibels of the sound power reduction. The effects of ejector dimensions on noise suppression and engine performance were investigated.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1958/naca-tn-4317.pdf