Wake flow-induced acoustic resonance around a long flat plate in a duct
Wake flow-induced acoustic resonance around a long flat plate in a duct
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DOI：
10.1134/s1810232815010051
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发表时间：
2015-01-01
影响因子：
2.4
通讯作者：
Bardakhanov, S. P.
中科院分区：
文献类型：
--
作者：
Katasonov, M. M.;Sung, H. J.;Bardakhanov, S. P.
当旋涡脱落产生的声频接近平板周围声模的频率时，长而薄的钝平板周围的流动产生声共振。在它们相互捕获之后，声音强度强烈地增加。为了更好地理解这一现象，在这里，我们调查的流动和流动诱导的声共振之间的相互作用，在管道中的长平板。随着流速的增加，观察到三种声共振模式。声共振行为作为前缘和后缘的形状（半圆形和正方形）和板的长度（39 a千分之一货币符号L/d a千分之一货币符号71）的函数来研究。基于板厚度和自由流流速的雷诺数范围为3300至21300。前缘分离泡和后缘尾流对声共振的影响是通过检查速度剖面，功率谱和压力声级来检查的。在共振状态下，在单色声下，尾流中流动分量的非线性行为被示出。不同形状的前缘和后缘在板周围的流动条件的差异导致不同的声流相互作用的效率，这导致不同的声级。结果表明，半圆形前缘和半圆形后缘的构型是产生气动声学共振的最佳构型。提出了可能的物理解释。
Flows around long thin blunt flat plates generate acoustic resonances when the sound frequency generated by the vortex shedding becomes close to the frequency of the acoustic mode around the plate. After their mutual capturing, the sound intensity strongly increases. To better understand this phenomenon, here we investigate the interaction between flow and flow-induced acoustic resonance around a long flat plate in a duct. Three acoustic resonance modes were observed as the flow velocity was increased. The acoustic resonance behavior is studied as a function of the shapes of the leading and trailing edges (semicircular and square) and the length of the plate (39 a parts per thousand currency sign L/d a parts per thousand currency sign 71). The Reynolds numbers based on the plate thickness and free-stream flow velocity ranged from 3300 to 21,300. The influence of the leading edge separation bubble and the trailing edge wake flow on the acoustic resonance is scrutinized by examining the velocity profiles, power spectra, and pressure sound level. The nonlinear behavior of the flow components in the wake is shown at monochromatic sound in the resonance regime. The difference in flow conditions around the plate for the diverse shapes of leading and trailing edges leads to the different efficiency of the sound-flow interaction, which originates the different sound level. It was found that the configuration with a semicircular leading edge and a semicircular trailing edge is the best one for generating aeroacoustic resonance. Possible physical explanations are proposed.