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The impact of subsonic twin jets on airport noise
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Bozak, Richard, F. |
| Copyright Year | 2012 |
| Description | Subsonic and supersonic aircraft concepts proposed through NASA s Fundamental Aeronautics Program have multiple engines mounted near one another. Engine configurations with multiple jets introduce an asymmetry to the azimuthal directivity of the jet noise. Current system noise predictions add the jet noise from each jet incoherently, therefore, twin jets are estimated by adding 3 EPNdB to the far-field noise radiated from a single jet. Twin jet effects have the ability to increase or decrease the radiated noise to different azimuthal observation locations. Experiments have shown that twin jet effects are reduced with forward flight and increasing spacings. The current experiment investigates the impact of spacing, and flight effects on airport noise for twin jets. Estimating the jet noise radiated from twin jets as that of a single jet plus 3 EPNdB may be sufficient for horizontal twin jets with an s/d of 4.4 and 5.5, where s is the center-to-center spacing and d is the jet diameter. However, up to a 3 EPNdB error could be present for jet spacings with an s/d of 2.6 and 3.2. |
| File Size | 1542184 |
| Page Count | 18 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20120013785 |
| Archival Resource Key | ark:/13960/t4vj0j67v |
| Language | English |
| Publisher Date | 2012-08-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Gas Jets Directivity Supersonic Aircraft Asymmetry Jet Aircraft Noise Aircraft Noise Subsonic Flow Spacing Noise Prediction Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
