Supersonic Jet Noise Investigation Using Jet Fluctuating Pressure Probes.
Final rept. May 71-Jun 72,
BOLT BERANEK AND NEWMAN INC CAMBRIDGE MASS
Pagination or Media Count:
Various mechanisms of jet noise generation are modeled using the fluctuating jet pressures to characterize the sources. The subsonic mixing mechanism is shown to dominate for sonic and mildly supersonic jets. An input-output relation between the jet pressure and sound pressure spectral densities is derived and verified. Fluctuating pressure probes are developed to measure sources of noise generation in sonic and supersonic jet exhausts. Jet exhausts with total temperatures as high as 3500F may be measured. Definitive data are obtained regarding the percentage of the sound radiated at a given angle and frequency by each region of the jet exhaust. Simple laser refraction experiments support the fluctuating pressure measurements. Modified author abstract
- Test Facilities, Equipment and Methods