| タイトル | Wind-tunnel fan noise reduction including effects of turning vanes on noise propagation |
| 著者（英） | Soderman, P. T.; Hoglund, L. E. |
| 著者所属（英） | Beam Engineering, Inc.|NASA Ames Research Center|Army Research and Technology Labs. |
| 発行日 | 1979-03-01 |
| 言語 | eng |
| 内容記述 | Fan silencers with low-pressure drop have been designed and installed in the NASA Ames 7- by 10-Foot Wind Tunnel No. 1. The silencers are composed of an absorbent lining flush with the wind-tunnel walls upstream of the fan and an absorbent splitter in the duct downstream of the fan. An acoustical insertion loss of 4 to 12 dB was measured between 100 and 1000 Hz. High-frequency performance of the silencers was reduced by test-section noise and by corner vanes which turned the sound waves so they followed the duct axis. Sound below 1.2 kHz diffracted around the 305-mm-long vanes and impinged on acoustically absorbent corner walls. Wind-tunnel flow losses are discussed. |
| NASA分類 | ACOUSTICS |
| レポートNO | 79A26934
AIAA PAPER 79-0642 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/428018 |
