Mechanisms and Active Control of Jet-Induced Noise
Mechanisms and Active Control of Jet-Induced Noise
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射流噪声的机理及主动控制
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
U. Rist
中科院分区：
文献类型：
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作者：
A. Babucke;B. Spagnoli;C. Airiau;M. Kloker;U. Rist
采用直接数值模拟的方法研究了喷流噪声的基本机理。在混合层中，相应的涡对的次谐波被发现是负责所产生的噪声的主要部分是在下游方向。通过修改引入的干扰之间的相移，可以减少或增强所发射的声音的相关部分。最优控制已成功地应用于平面混合层。在远场，可以降低平均噪声水平。根据测量线的不同，通过控制产生一些分布式控制或抗噪声。通过添加代表喷嘴端部的分流板来实现更真实的配置。矩形锯齿导致大的相干展向涡结构的崩溃，从而提供9dB的噪声降低。
Fundamental mechanisms of jet noise are investigated by means of direct numerical simulation. In the mixing layer, subharmonics of the respective vortex pairing are found to be responsible for the main part of the generated noise which is directed in downstream direction. By modifying the phase shift between introduced disturbances it is possible to diminish or enhance relevant portions of the emitted sound. Optimal control has been applied successfully to a plane mixing layer. In the far field, the mean noise level could be reduced. Depending on the measurement line, some distributed control or anti-noise is generated by the control. A more realistic configuration is achieved by adding a splitter plate representing the nozzle end. Rectangular serrations lead to a breakdown of the large coherent spanwise vortical structures and thus provide a noise reduction of 9dB.