| タイトル | Acoustic Efficiency of Azimuthal Modes in Jet Noise Using Chevron Nozzles |
| 本文（外部サイト） | http://hdl.handle.net/2060/20070003489 |
| 著者（英） | Brown, Clifford A.; Bridges, James |
| 著者所属（英） | NASA Glenn Research Center |
| 発行日 | 2006-12-01 |
| 言語 | eng |
| 内容記述 | The link between azimuthal modes in jet turbulence and in the acoustic sound field has been examined in cold, round jets. Chevron nozzles, however, impart an azimuthal structure on the jet with a shape dependent on the number, length and penetration angle of the chevrons. Two particular chevron nozzles, with 3 and 4 primary chevrons respectively, and a round baseline nozzle are compared at both cold and hot jet conditions to determine how chevrons impact the modal structure of the flow and how that change relates to the sound field. The results show that, although the chevrons have a large impact on the azimuthal shape of the mean axial velocity, the impact of chevrons on the azimuthal structure of the fluctuating axial velocity is small at the cold jet condition and smaller still at the hot jet condition. This is supported by results in the azimuthal structure of the sound field, which also shows little difference in between the two chevron nozzles and the baseline nozzle in the distribution of energy across the azimuthal modes measured. |
| NASA分類 | Aircraft Propulsion and Power |
| レポートNO | NASA/TM-2006-214364
AIAA Paper 2006-2654
E-15640 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/259195 |
