An investigation of the mechanisms of sound generation in initially laminar subsonic jets using the Goldstein acoustic analogy
An investigation of the mechanisms of sound generation in initially laminar subsonic jets using the Goldstein acoustic analogy
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使用戈德斯坦声学类比研究初始层流亚音速射流的声音产生机制
DOI：
10.1017/jfm.2012.448
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发表时间：
2013
影响因子：
3.7
通讯作者：
Karabasov S
中科院分区：
文献类型：
--
作者：
Karabasov S
使用Goldstein声学类比研究了两个初始层流亚音速射流内对应于不同流入条件的声源的细节，一个是完全层流的，另一个是喷嘴边界层强迫的。声学模拟等效源的统计数据产生的大涡模拟（LES）和这些有效性的范围相关的问题进行了探讨。各种源项的预测比较重要性证实了以前的研究结果，除了一个额外的长期，涉及纵向和横向源组件。协议在1分贝的频率范围内从Strouhal数，这被证明是最好的对应的有效范围内的声源模型的LES数据可用，被发现之间的噪声预测使用的声学模拟模型和那些以前进行的LES-ILEE（各向同性线性化欧拉方程）控制面方法的名义层流流入射流的情况。声学类比是用来确定源的长度尺度，有助于噪声在不同的辐射角的射流，它们是如何分布的，以及它们如何随着流入条件的变化而变化。对于涡对频率，采用基于相关长度尺度的声源分解技术，发现了两类噪声源：一类位于射流上游端，与涡对相关，对应于声源振幅峰值;另一个，这是占主导地位的来源，与射流混合在射流潜在的核心结束。它还表明，边界层强迫导致减少的贡献，大的源长度尺度的噪声与完全层流的情况下。
The details of the sound sources within two initially laminar subsonic jets corresponding to different inflow conditions, one fully laminar and the other with nozzle boundary layer forcing, are studied using the Goldstein acoustic analogy. The statistics of the acoustic analogy equivalent sources are generated from large eddy simulations (LES) and issues associated with the range of validity of these are explored. The predicted comparative importance of various source terms confirms the results of previous studies, with the exception of one extra term that involves the longitudinal and the lateral source components. Agreement within 1 dB over the frequency range from Strouhal number , which was shown to best correspond to the validity range of the acoustic source model for the LES data available, is found between noise predictions using the acoustic analogy model and those of a previously conducted LES–ILEE (isotropic linearized Euler equation) control surface method for the nominally laminar inflow jet case. The acoustic analogy is used to determine the source length scales which contribute to noise at different radiated angles to the jet, how they are distributed and how they change with change of inflow conditions. For the vortex pairing frequency, using a new acoustic source decomposition technique based on the correlation length scale, two types of noise sources are found. One source, which corresponds to the peak source amplitude, is located at the upstream end of the jet and is associated with the vortex pairing. The other one, which is the dominant source, is associated with jet mixing at the end of the jet potential core. It is also shown that boundary layer forcing leads to a reduction in the contribution to the noise of the large source length scales in comparison with the fully laminar case.
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影响因子：
1
作者：
M. Goldstein
通讯作者：
M. Goldstein
高亚音速喷气机的声学特性
DOI：
--
发表时间：
1970
期刊：
影响因子：
--
作者：
L. Maestrello;E. Mcdaid
通讯作者：
E. Mcdaid
声学作为流体力学的一个分支
影响因子：
3.7
作者：
D. Crighton
通讯作者：
D. Crighton
使用声学类比统计方法计算初始层流射流的噪声：应用和讨论
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
S. Karabasov;C. Bogey;T. Hynes
通讯作者：
T. Hynes
影响因子：
1
作者：
K. Viswanathan
通讯作者：
K. Viswanathan