ACOUSTIC IDENTIFICATION OF COHERENT STRUCTURES IN A TURBULENT JET
ACOUSTIC IDENTIFICATION OF COHERENT STRUCTURES IN A TURBULENT JET
复制标题
湍流射流中相干结构的声学识别
DOI：
10.1006/jsvi.2002.5130
复制
发表时间：
2003
影响因子：
4.7
通讯作者：
A. Ragni
中科院分区：
文献类型：
--
作者：
G. Guj;M. Carley;R. Camussi;A. Ragni
摘要通过调节远场声测量的来流速度和压力信号，导出亚音速射流中与噪声产生相关的流体动力学事件。喷流位于消声室中，远场噪声测量与进流风速计和声学测量同时进行，距离喷嘴的距离为x（0 × x/D × 20，D为喷流直径）。然后，实验数据进行了分析与条件平均程序使用的峰值作为触发器的声学信号。该方法的分析开发和支持数值模拟。平均过程允许识别与流中的噪声生成相干结构相关联的流入速度和压力的平均时间特征、它们在发射时刻的位置以及它们的时间统计。然后讨论了与平均时间特征相关联的事件的物理性质。
Abstract Fluid-dynamic events associated with noise generation in a subsonic jet are educed by conditioning in-flow velocity and pressure signals on farfield sound measurements. The jet is located in an anechoic chamber, and farfield noise measurements are performed simultaneously with in-flow anemometric and acoustic measurements at a number of distances x from the nozzle (0⩽x/D⩽20, with D the jet diameter). The experimental data are then analyzed with a conditional averaging procedure using peaks in the acoustic signal as a trigger. An analysis of the method is developed and supported by numerical simulations. The averaging procedure permits the identification of the average time signatures of in-flow velocity and pressure associated with noise-generating coherent structures in the flow, their position at the emitting instants and their temporal statistics. The physical properties of the events associated with the averaged time signatures are then discussed.