The analysis and simulation of compressible turbulence
The analysis and simulation of compressible turbulence
复制标题
可压缩湍流分析与模拟
DOI：
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发表时间：
1990
影响因子：
3.4
通讯作者：
S. Sarkar
中科院分区：
文献类型：
--
作者：
G. Erlebacher;M. Y. Hussaini;H. Kreiss;S. Sarkar
本文考虑低湍流马赫数下的可压缩湍流流动。与这种流动几乎不可压缩（即，速度场的发散始终保持小），表明即使初始速度场的发散小到可以忽略不计，它也可以在脉动马赫数量级的无量纲时间尺度上迅速增长。一个渐近理论，使其描述的自由发散和自由涡分量的流动已被开发来解决初值问题。结果，各种类型的低马赫数湍流区已被分类相对于初始条件。公式推导出，准确地预测后的初始瞬态已经消失的压缩性水平。这些结果被广泛的各向同性湍流的直接数值模拟所证实。
This paper considers compressible turbulent flows at low turbulent Mach numbers. Contrary to the general belief that such flows are almost incompressible (i.e., the divergence of the velocity field remains small for all times), it is shown that even if the divergence of the initial velocity field is negligibly small, it can grow rapidly on a nondimensional time scale which is the order of the fluctuating Mach number. An asymptotic theory which enables a description of the flow in terms of its divergence-free and vorticity-free components has been developed to solve the initial-value problem. As a result, the various types of low Mach number turbulent regimes have been classified with respect to the initial conditions. Formulae are derived that accurately predict the level of compressibility after the initial transients have disappeared. These results are verified by extensive direct numerical simulations of isotropic turbulence.