A Study of the Correlation of Large-Scale Structure Dynamics and Far-Field Radiated Noise in an Excited Mach 0.9 Jet
A Study of the Correlation of Large-Scale Structure Dynamics and Far-Field Radiated Noise in an Excited Mach 0.9 Jet
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0.9 马赫激发射流中大尺度结构动力学与远场辐射噪声的相关性研究
DOI：
10.1260/147547208786940008
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发表时间：
2009
影响因子：
1
通讯作者：
M. Samimy
中科院分区：
文献类型：
--
作者：
J. Kastner;Jin;M. Samimy
本工作的主要目的是激发红线为0.76×106的轴对称马赫0.9喷流的各种不稳定性，跟踪随后的大尺度结构/不稳定波，并研究这些结构的动力学与远场声场之间的关系。8个局域弧丝等离子体激励器在大范围的Strouhal数和几种方位模式下激励射流，这些激励器沿喷嘴圆周等间距分布在喷嘴出口附近。利用粒子图像测速仪和12个传声器组成的三维阵列，在与下游射流轴成30°的极角处，对流场和远场噪声进行了研究。麦克风阵列的结果表明，辐射到30°极角的高幅噪声恰好起源于势芯末端的下游，这与我们以前的结果和文献中的结果是一致的。沿流方向的噪声源分布只对喷流优先模式周围的方位向模式敏感。另外，总的趋势是强迫低Strouhal数的急流将分布向上游移动，而当Strouhal数较高时，源分布与基线急流相似。使用条件平均的PIV数据来关联流动动力学和噪声源。条件平均速度脉动沿射流中心线的增长、饱和和衰减与远场噪声和使用麦克风阵列估计的噪声源分布有很好的相关性。对于喷流柱Strouhal数附近的m=0模激励，条件平均速度脉动与噪声源分布有很好的相关性。而当m=1时，与条件平均的跨河波动的相关性最好。
The main goal of the present work is to excite various instabilities of an axisymmetric Mach 0.9 jet with a ReD of 0.76 × 106, track the ensuing large-scale structures/instability waves, and investigate relations between the dynamics of these structures and the far-field sound. The jet was excited over a large range of Strouhal numbers and several azimuthal modes by eight localized arc filament plasma actuators, equally spaced around the circumference of the nozzle, near the nozzle exit. The flow field and far-field noise were investigated using particle image velocimetry and a three-dimensional array of 12 microphones at 30° polar angle to the downstream jet axis. The microphone array results show that the high amplitude noise radiated to 30° polar angle is originated just downstream of the end of the potential core, in agreement with our previous results and the results in the literature. The streamwise noise source distribution was only sensitive to azimuthal modes around the jet preferred mode. Otherwise, the general trend was that forcing the jet at low Strouhal numbers moves the distribution upstream compared to the baseline jet, and at high Strouhal numbers results in a source distribution similar to the baseline jet. ***Conditionally-averaged PIV data were used to relate the flow dynamics and noise sources. The growth, saturation, and decay of the conditionally-averaged velocity fluctuations along the jet centerline correlate well with the far-field noise and the noise source distribution estimated using the microphone array. For m = 0 mode excitation around the jet column Strouhal number, the conditionally-averaged streamwise velocity fluctuations correlate well with the noise source distribution. While for m = 1, the correlation is best with the conditionally-averaged cross-stream fluctuations.
DOI：
10.1007/978-3-540-39914-8
发表时间：
2004-03
期刊：
--
影响因子：
--
作者：
A. S. Ginevsky;Ye. V. Vlasov;R. Karavosov
通讯作者：
A. S. Ginevsky;Ye. V. Vlasov;R. Karavosov