The influence of a pressure wavepacket's characteristics on its acoustic radiation.
The influence of a pressure wavepacket's characteristics on its acoustic radiation.
复制标题
压力波包特性对其声辐射的影响。
DOI：
10.1121/1.4921031
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
F. Margnat
中科院分区：
文献类型：
--
作者：
R. Serré;J. Robinet;F. Margnat
通过齐次波动方程的边界条件，用压力波包激励声介质来模拟流动产生的噪声。压力波包是流动非定常的一般表示，具有伪高斯型空间包络和亚音速相速度的特征。空间调制在波数谱的超音速范围内产生能量，这直接与声辐射和方向性有关。采用定义为波包产生的声功率与模拟流动的声功率之比的声学效率，对包络形状对噪声发射的影响进行了解析和数值研究。该方法还扩展到均匀运动介质中的声波传播的情况，拓宽了实际流动的可能性，其中有组织的结构起主要作用，例如绕巡航射流、空腔和湍流边界层流动的同流。声学效率的结果表明，声压水平是显著的，特别是在运动介质中辐射的非对称波包。
Noise generation by flows is modeled using a pressure wavepacket to excite the acoustic medium via a boundary condition of the homogeneous wave equation. The pressure wavepacket is a generic representation of the flow unsteadiness, and is characterized by a space envelope of pseudo-Gaussian shape and by a subsonic phase velocity. The space modulation yields energy in the supersonic range of the wavenumber spectrum, which is directly responsible for sound radiation and directivity. The influence of the envelope's shape on the noise emission is studied analytically and numerically, using an acoustic efficiency defined as the ratio of the acoustic power generated by the wavepacket to that involved in the modeled flow. The methodology is also extended to the case of acoustic propagation in a uniformly moving medium, broadening possibilities toward practical flows where organized structures play a major role, such as co-flow around cruising jet, cavity, and turbulent boundary layer flows. The results of the acoustic efficiency show significant sound pressure levels, especially for asymmetric wavepackets radiating in a moving medium.
影响因子：
--
作者：
AVITAL E
通讯作者：
AVITAL E
层流射流中的无声基流和声源。
DOI：
10.1121/1.3672804
发表时间：
2012
期刊：
The Journal of the Acoustical Society of America
影响因子：
--
作者：
Sinayoko S
通讯作者：
Sinayoko S