Temporal instability modes of supersonic round jets
Temporal instability modes of supersonic round jets
复制标题
超音速圆形射流的时间不稳定模式
DOI：
10.1017/s0022112010003150
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发表时间：
2010
影响因子：
3.7
通讯作者：
S. L. Dizes
中科院分区：
文献类型：
--
作者：
L. Parras;S. L. Dizes
在这项研究中，一个全面的无粘时间稳定性分析的可压缩圆形射流的马赫数范围从1到10。我们表明，除了开尔文-亥姆霍兹不稳定模式，存在每个方位波数的其他三种类型的模式（逆流亚声波，亚声波和超声波），其特点进行了详细分析，使用WKBJ理论在大轴向波数的限制。该理论适用于任何速度和温度分布。它提供了相速度和空间结构的模式，并定性地描述了基流修改的模式特性的影响。理论预测与数值计算结果进行了比较，双曲正切模型和一个很好的协议证明。结果也进行了讨论的背景下，喷气噪声。我们展示了如何使用该理论来确定先验的喷气修改不稳定引起的噪声的影响。
In this study, a comprehensive inviscid temporal stability analysis of a compressible round jet is performed for Mach numbers ranging from 1 to 10. We show that in addition to the Kelvin–Helmholtz instability modes, there exist for each azimuthal wavenumber three other types of modes (counterflow subsonic waves, subsonic waves and supersonic waves) whose characteristics are analysed in detail using a WKBJ theory in the limit of large axial wavenumber. The theory is constructed for any velocity and temperature profile. It provides the phase velocity and the spatial structure of the modes and describes qualitatively the effects of base-flow modifications on the mode characteristics. The theoretical predictions are compared with numerical results obtained for an hyperbolic tangent model and a good agreement is demonstrated. The results are also discussed in the context of jet noise. We show how the theory can be used to determine a priori the impact of jet modifications on the noise induced by instability.