| タイトル | Effects of flight on noise radiated from convected ring sources in coaxial dual flow. Part 2: The noise from heated jets |
| 本文（外部サイト） | http://hdl.handle.net/2060/19830008966 |
| 著者（英） | Dash, R. |
| 著者所属（英） | Stanford Univ. |
| 発行日 | 1982-08-01 |
| 言語 | eng |
| 内容記述 | The effects of flight on noise from heated jets are discussed. The effects of the additionally, extraneously-generated dipole and simple source terms which arise as a result of the density gradients across the fluid interfaces were incorporated. The coaxial flows with inverted profiles are shown to be quieter than the conventional profiles; however, the benefit of noise reduction at higher outer-to-inner area ratios is totally offset as the inverted profile incurs a significant massloss and thrust-loss. Amongst all the possible coaxial configurations when on of the coaxial streams is heated-conventional profile (CP), inverted profile (IP) and the variable stream control engine (VSCE) cycle-and at constant massflow and thrust, a VSCE-cycle is the most desirable and the best possible engine cycle inasmuch as it provides over more than 18.0 dB reduction in SPL (as compared against noise from a CP-cycle) at all angles, both statically and in flight, for area ratios Sigma 0.25. |
| NASA分類 | ACOUSTICS |
| レポートNO | 83N17237
NASA-CR-169736
SU-JIAA-TR-48-PT-2
NAS 1.26:169736 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/163640 |
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