Statistical Models of Large Scale Turbulent Flow

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• 作者：J. J. H. Brouwers
• 刊名：Flow, Turbulence and Combustion
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：97
• 期：2
• 页码：369-399
• 全文大小：884 KB
• 刊物类别：Engineering
• 刊物主题：Physics
  Mechanics
  Automotive Engineering
  
• 出版者：Springer Netherlands
• ISSN：1573-1987
• 卷排序：97

文摘

The Langevin and diffusion equations for statistical velocity and displacement of marked fluid particles are formulated for turbulent flow at large Reynolds number for which Lagrangian Kolmogorov K-41 theory holds. The damping and diffusion terms in these equations are specified by the first two terms of a general expansion in powers of \(C_{0}^{-1}\) where C₀ is Lagrangian based universal Kolmogorov constant: \(6\lesssim C_{0}\lesssim 7\). The equations enable the derivation of descriptions for transport by turbulent fluctuations of conserved scalars, momentum, kinetic energy, pressure and energy dissipation as a function of the derivative of their mean values. Except for pressure and kinetic energy, the diffusion coefficients of these relations are specified in closed-form with \(C_{0}^{-1}\) as constant of proportionality. The relations are verified with DNS results of channel flow at Re_τ=2000. The presented results can serve to improve or replace the diffusion models of current CFD models.KeywordsLangevin equationDiffusion equationAnisotropic turbulenceKolmogorov theory