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Noise characteristics of overexpanded jets from convergent-divergent nozzles
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Zaman, K. B. M. Q. |
| Copyright Year | 2008 |
| Description | A broadband noise component occurring in the overexpanded flow regime with convergent-divergent nozzles is identified. Relative to a convergent nozzle, at same pressure ratios, this excess noise can lead to a large increase in the overall sound pressure levels. Several features distinguish it from the more familiar broadband shock associated noise. Unlike the latter, it is observed even at shallow polar locations and there is no noticeable shift of the spectral content in frequency with observation angle. The amplitudes are found to be more pronounced with nozzles having larger half-angle of the divergent section. The noise apparently occurs when a shock resides within the divergent section of the nozzle and results from random unsteady motion of the shock. |
| File Size | 819877 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20080006071 |
| Archival Resource Key | ark:/13960/t5v74dj9b |
| Language | English |
| Publisher Date | 2008-01-07 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Position Location Nozzle Design Turbulent Flow Jet Flow Broadband Convergent-divergent Nozzles Pressure Ratio Frequencies Noise Measurement Aeroacoustics Mach Number Sound Pressure Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
