Noise and Emission Research Group, National Aerospace Laboratory(NAL)
Noise and Emission Research Group, National Aerospace Laboratory(NAL)
出版者
航空宇宙技術研究所
出版者(英)
National Aerospace Laboratory(NAL)
雑誌名
航空宇宙技術研究所報告
雑誌名(英)
Technical Report of National Aerospace Laboratory TR-770
巻
770
ページ
11
発行年
1983-07
抄録(英)
The combination of a circular fan/elliptic core nozzle was tested and compared with the results of a conventional circular core/circular fan nozzle under static flow conditions. The results show that there occurred a change of the directiveness of jet noize around the nozzle when using the circular/elliptic nozzle combination. In a 30~50deg direction from the jet axis, a 3~5 dB reduction was observed. We measured radial velocity distribution by using LDV and axial sound source distribution by the polar correlation method in an anechoic room. Based on these measurments we discuss, in this paper, the relation between sound pressure generation and velocity distribution around the exhaust nozzle. We recommend herein a circular/elliptic nozzle combination for turbo-fan engine exhaust nozzle.