Higher-order dissipation in the theory of homogeneous isotropic turbulence
Higher-order dissipation in the theory of homogeneous isotropic turbulence
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DOI：
10.1017/jfm.2016.489
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发表时间：
2016-08
影响因子：
3.7
通讯作者：
N. Peters;J. Boschung;M. Gauding;J. Goebbert;R. Hill;H. Pitsch
中科院分区：
文献类型：
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作者：
N. Peters;J. Boschung;M. Gauding;J. Goebbert;R. Hill;H. Pitsch
将均匀各向同性湍流的两点理论推广到高阶结构函数方程中的源项。为此，导出了这些源项的输运方程。我们专注于所得到的方程，这是特别感兴趣的，因为它是不变的，因此独立于坐标系的跟踪。在偶次源项方程的追踪中，我们发现耗散分布的高阶矩，个别偶次源项方程包含纵向、横向和混合耗散分布函数的高阶矩。这表明第一次耗散波动，其中大多数的唯象不稳定性模型的基础上，包含在Navier-Stokes方程。值得注意的是，我们还发现Kolmogorov（J. Fluid Mech.，第13卷，1962年，第13页。82-85），因为它与耗散相关性有关。
The two-point theory of homogeneous isotropic turbulence is extended to source terms appearing in the equations for higher-order structure functions. For this, transport equations for these source terms are derived. We focus on the trace of the resulting equations, which is of particular interest because it is invariant and therefore independent of the coordinate system. In the trace of the even-order source term equation, we discover the higher-order moments of the dissipation distribution, and the individual even-order source term equations contain the higher-order moments of the longitudinal, transverse and mixed dissipation distribution functions. This shows for the first time that dissipation fluctuations, on which most of the phenomenological intermittency models are based, are contained in the Navier–Stokes equations. Noticeably, we also find the volume-averaged dissipation $\unicode[STIX]{x1D700}_{r}$ used by Kolmogorov (J. Fluid Mech., vol. 13, 1962, pp. 82–85) in the resulting system of equations, because it is related to dissipation correlations.