Flow and Acoustic Measurements on a Convergent Nozzle Supersonic Jet Ejector,
Abstract
A conical convergent nozzle with a throat diameter of 2 inches was used to give a Mach number 1.5 room temperature primary jet with which various combinations of rods, shroud and induced flow were investigated as noise suppresors. Small shock wave disturbances were found to be extremely effective in reducing the supersonic region of the jet and accelerating the mixing between the primary and secondary jets within the shroud. These effects can result in as much as 17 db acoustic power level reduction. From aerodynamic measurements at the shroud exit, the amount of sound power reduction, calculated on the basis of the unbounded mixing with the ambient of the reduced velocity mixed primary and secondary jets, was far from achieved due to noise sources within the shroud. These sources caused by shock waves and the internal primary and secondary jet mixing can increase the free stream turbulence level of the mixed jets. The acoustic power level spectra of the ejector noise shows it to be broadband. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1969
- Accession Number
- AD0754260
Entities
People
- H. T. Nagamatsu
- R. E. Sheer Jr.
- W. T. Pettit
Organizations
- General Electric