Instability of vortical and acoustic modes in supersonic round jets
Instability of vortical and acoustic modes in supersonic round jets
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超音速圆形射流中涡流和声学模式的不稳定性
DOI：
10.1063/1.869196
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发表时间：
1997
影响因子：
4.6
通讯作者：
N. Sandham
中科院分区：
文献类型：
--
作者：
K. Luo;N. Sandham
用可压缩流动的无粘线性稳定性理论研究了“顶帽”型和完全发展的射流型的稳定性。研究范围很广，包括马赫数和温度比。发现了两种类型的不稳定性：涡旋和声学，每一种都可以细分为非辐射（亚音速）和辐射（超音速）模式。涡旋模是不可压缩流的开尔文-亥姆霍兹不稳定性的延续。声学模态是一种可压缩流动现象，这在大马赫数下变得非常重要。温度比效应可以是不稳定的，也可以是稳定的，这取决于马赫数和不稳定的模式。在完全发展的射流中发现了不稳定声模谱，包括轴对称声模。对于这种射流，在马赫数超过3时，声轴对称波比旋涡波和声螺旋波更不稳定。声学模式的共振机制的有力证据可以在gro中看到。
The stability of “top-hat” and fully developed jet profiles is investigated by an inviscid linear stability theory for compressible flow. The study covers a wide range of the Mach number and the temperature ratio. Two types of instabilities are found: vortical and acoustic, each of which can be subdivided into non-radiating (subsonic) and radiating (supersonic) modes. The vortical mode is the continuation of the Kelvin-Helmholtz instability from incompressible flow. The acoustic mode is a compressible flow phenomenon, which becomes important at large Mach numbers. Temperature-ratio effects can be destabilizing or stabilizing, depending on the Mach number and mode of instability. A spectrum of unstable acoustic modes, including axisymmetric ones, are found to exist in the fully developed jet. For this jet, acoustic axisymmetric waves become more unstable than both vortical and acoustic helical waves at Mach numbers over about 3. Strong evidence of a resonance mechanism for acoustic modes is seen in the gro...