Journal ArticleDOI
Measurements of the Small-Scale Structure of Turbulence at Moderate Reynolds Numbers
J. C. Wyngaard,H. Tennekes +1 more
TLDR
In this article, the first two time derivatives of the streamwise velocity fluctuation in a mixing layer are presented, and the probability distributions of squared derivatives are found to be nearly log normal.Abstract:
Measurements of probability densities and distributions, moments, and spectra obtained from the first two time derivatives of the streamwise velocity fluctuation in a mixing layer are presented. Probability distributions of squared derivatives are found to be nearly log normal. The skewness (S) and kurtosis (K) of the first derivative are compared with new atmospheric data at much higher Reynolds numbers. Reynolds-number dependence is indicated, in conflict with universal equilibrium theory. A modified theory using fluctuating dissipation predicts that S and K have power-law behavior with turbulent Reynolds number and are related by S ∝ K3/8, in general agreement with the trends of the limited data available.read more
Citations
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Book ChapterDOI
Two-Point Homogeneous Turbulence
TL;DR: In this paper, the mean flow equations were solved, together with transport equations for one or two scalar quantities (like K and e) describing characteristic time and length scales of turbulence which are processed throughout the flow without requiring detailed forms adequate to a particular zone of the flow.
DissertationDOI
Fine Scale Velocity Measurements in a Turbulent Jet in a Confined Crossflow.
TL;DR: In this article , the fine scale velocity field of a turbulent jet in a confined crossflow was measured by laser velocimetry, with a crossflow velocity of 10.0 m/sec.
Book ChapterDOI
Principles of Turbulent Flow Modeling
TL;DR: In this paper, the authors developed engineering means that allow the study of turbulent viscous flows for which the Reynolds number is high enough to explain the high level of effective diffusivity.
Statistical properties of energy dissipation
TL;DR: In this article, the LNH was confirmed and the universal parameter of the lognormal hypothesis was evaluated in different ways, yielding: Μ = 0.5 (from structure functions of u) and Μ= 0.47 (from dissipation spectra).
References
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Book
The theory of homogeneous turbulence
TL;DR: In this article, the kinematics of the field of homogeneous turbulence and the universal equilibrium theory of decay of the energy-containing eddies are discussed. But the authors focus on the dynamics of decay and not on the probability distribution of u(x).