Sound from boundary layer flow over steps and gaps
Sound from boundary layer flow over steps and gaps
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来自边界层的声音流过台阶和间隙
DOI：
10.1016/j.jsv.2014.03.042
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发表时间：
2010
影响因子：
4.7
通讯作者：
S. Glegg
中科院分区：
文献类型：
--
作者：
M. R. Catlett;W. Devenport;S. Glegg
这项研究是关于小的前进和后退台阶和相似尺寸的缝隙结构的边界层流动的辐射声。这些测量是在弗吉尼亚理工大学消音壁喷气设施中进行的，台阶高度大约是进入边界层高度的10%到100%。结果表明，台阶高度和边界层边界速度对前台阶和后台阶的远场声场有较大影响。两个震源都没有表现出明显的偶极方向性，至少在这项研究中考虑的较大的台阶高度在声学上并不是紧凑的。提出了一种新的混合标度归一化方法，用于计算这两种类型的STEP的远场谱。研究表明，与同等大小的向前台阶相比，后退台阶产生的远场声音要弱得多。对于从各种间隙流测量到的远场声，讨论了这一行为的含义。
This study is concerned with the radiated sound from boundary layer flows over small forward and backward steps and gap configurations of similar dimension. These measurements were performed in the Virginia Tech Anechoic Wall Jet Facility for step heights that ranged from approximately 10 percent to 100 percent of the incoming boundary layer height. The results show the influence of step height and boundary layer edge velocity on the far-field sound from forward and backward steps. Neither source shows clear dipole directivity and at least the larger step heights considered in this study are shown to not be acoustically compact. A new mixed scaling normalization is proposed for the far-field spectra from both types of step. Backward steps are shown to be much weaker producers of far-field sound than similarly sized forward steps. The implications of this behavior are discussed with respect to the far-field sound measured from various gap flows.