| タイトル | Some Acoustic Results from the Pratt and Whitney Advanced Ducted Propulsor: Fan 1 |
| 本文（外部サイト） | http://hdl.handle.net/2060/19990031947 |
| 著者（英） | Bock, Lawrence A.; Dittmar, James H.; Elliott, David M. |
| 著者所属（英） | NASA Glenn Research Center |
| 発行日 | 1999-03-01 |
| 言語 | eng |
| 内容記述 | Noise measurements were obtained for the Advanced Ducted Propulsor (ADP) - Fan 1, with and without nacelle acoustic treatment. The fan was tested with no acoustic treatment (hard wall) and with acoustic treatment installed in three configurations in the nacelle (mid, mid plus aft, fully treated). The hard wall results showed that the radiated noise from the fan came primarily from the aft end of the nacelle. At takeoff and higher speeds, the noise measured at the inlet angles was also found to be dominated by noise from the aft end. Significant amounts of attenuation were observed with acoustic treatment installed and comparison with predictions showed the treatment gave more attenuation than predicted. Effective Perceived Noise Levels were determined for a large hypothetical 4 engine airplane. These levels showed that the installed acoustic treatment provided as much as 5 EPNdB of noise reduction. A traverse with a probe having three microphones, one above the other, showed azimuthal variations in the noise that need to be further investigated. |
| NASA分類 | Acoustics |
| レポートNO | NAS 1.15:209049
E-11582
NASA/TM-1999-209049 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/96590 |
