Physics of Fluids - Publications

Intermittency exponents

Europhysics Letters 21, 201 (1993)

Authors

	Siegfried Grossmann
	Detlef Lohse

BibTeΧ

@article{0295-5075-21-2-014,
  author={S. Grossmann and D. Lohse},
  title={Intermittency Exponents},
  journal={EPL (Europhysics Letters)},
  volume={21},
  number={2},
  pages={201},
  url={http://stacks.iop.org/0295-5075/21/i=2/a=014},
  year={1993},
  abstract={Intermittency is commonly connected with non-Gaussian fluctuations of the velocity gradients. Here we show that the r -scaling exponents μ( q ) of the moments of the locally averaged energy dissipation ("intermittency exponents") are nonzero even for a Gaussian probability distribution of the velocity gradients. This casts–at least for finite Reynolds numbers–additional doubts on the use of Kolmogorov and Obukhov's refined similarity hypothesis which leads to ζ( m ) = m /3 - μ( m /3) for the scaling exponents of the velocity structure functions. Instead, we can use the presumed universality ( i.e. independence of the Taylor-Reynolds number) of the μ( q ) to predict the degree of the non-Gaussian character of the ∂ 1 u 1 probability distribution. We explicitly evaluate the Re λ -dependence of its stretching exponent β together with the Re λ -scaling exponent of the hyperflatnesses F ( q ) . Both are found to be in agreement with recent experiments.}
}