Loading...
Please wait, while we are loading the content...
Similar Documents
Noise measurements from an ejector suppressor nozzle in the nasa lewis 9- by 15-foot low speed wind tunnel
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Krejsa, Eugene A. Cooper, Beth A. Hall, David G. Khavaran Sr., Abbas |
| Copyright Year | 1990 |
| Description | Acoustic results are presented of a cooperative nozzle test program between NASA and Pratt and Whitney, conducted in the NASA-Lewis 9 x 15 ft Anechoic Wind Tunnel. The nozzle tested was the P and W Hypermix Nozzle concept, a 2-D lobed mixer nozzle followed by a short ejector section made to promote rapid mixing of the induced ejector nozzle flow. Acoustic and aerodynamic measurements were made to determine the amount of ejector pumping, degree of mixing, and noise reduction achieved. A series of tests were run to verify the acoustic quality of this tunnel. The results indicated that the tunnel test section is reasonably anechoic but that background noise can limit the amount of suppression observed from suppressor nozzles. Also, a possible internal noise was observed in the air supply system. The P and W ejector suppressor nozzle demonstrated the potential of this concept to significantly reduce jet noise. Significant reduction in low frequency noise was achieved by increasing the peak jet noise frequency. This was accomplished by breaking the jet into segments with smaller dimensions than those of the baseline nozzle. Variations in ejector parameters had little effect on the noise for the geometries and the range of temperatures and pressure ratios tested. |
| File Size | 26719159 |
| Page Count | 62 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19910002180 |
| Archival Resource Key | ark:/13960/t2x39pr1s |
| Language | English |
| Publisher Date | 1990-10-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Jet Aircraft Noise Noise Reduction Low Speed Wind Tunnels Two Dimensional Flow Noise Measurement Background Noise Suppressors Turbulent Mixing Nozzle Geometry Exhaust Nozzles Nozzle Flow Ejectors Wind Tunnel Tests Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
