da Silva Filipe D, Jordan Peter, Cavalieri André V G
TEG Thermofluids Engineering Group, Federal University of Santa Catarina, Joinville-Santa Catarina, 89219-600, Brazil.
PPRIME Institute, CNRS-ENSMA-University of Poitiers, Poitiers, 86036, France.
J Acoust Soc Am. 2019 Dec;146(6):4472. doi: 10.1121/1.5140190.
An investigation of a wavepacket model for free-jet and jet-surface interaction noise was conducted. The source term for the axisymmetric mode was extracted from a Mach 0.9 jet large eddy simulation and employed to adjust the parameters of a simple source model. Streamwise coherence decay, in particular, was considered. The source model was propagated with both the free-field and tailored Green's function for a semi-infinite flat plate positioned at a distance of r/D = 1 from the jet axis. Significant deviations were observed in the prediction of the low-angle directivity of the isolated jet as well as in the reproduction of the characteristics of the source field. However, the effects of trailing edge noise were well reproduced. The installed jet case, at the region dominated by trailing-edge scattering, showed very little sensitivity to the coherence decay, a crucial feature in the isolated jet case. In this sense, the modelling of the installed-jet case proved to be much simpler.
对自由射流和射流-表面相互作用噪声的波包模型进行了研究。轴对称模式的源项从马赫数为0.9的射流大涡模拟中提取，并用于调整简单源模型的参数。特别考虑了流向相干性衰减。源模型通过自由场格林函数和为位于距射流轴线r/D = 1处的半无限平板定制的格林函数进行传播。在孤立射流低角度指向性的预测以及源场特征的再现方面观察到了显著偏差。然而，后缘噪声的影响得到了很好的再现。在由后缘散射主导的区域，安装射流的情况对相干性衰减的敏感性非常小，这是孤立射流情况的一个关键特征。从这个意义上说，安装射流情况的建模被证明要简单得多。
