Book ChapterDOI
Coherent Structures in Turbulence
John L. Lumley
- pp 215-242
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TLDR
In this article, a technique for calculating organized structures in turbulent shear flows is proposed, based on a homogeneous function decomposition and involves representation of a random function as a series of coherent structures occurring at stochastic locations with sparsity.Abstract:
A technique is proposed for calculating organized structures in turbulent shear flows. The proposed approach is based on a homogeneous function decomposition and involves representation of a random function as a series of coherent structures occurring at stochastic locations with stochastic strengths. Attention is given to the retrieval of phase information and information on overlap and spacing, nearly parallel shear flows, dynamical equations, and applications to measurements.read more
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Journal ArticleDOI
On the identification of a vortex
Jinhee Jeong,Fazle Hussain +1 more
TL;DR: In this article, the authors propose a definition of vortex in an incompressible flow in terms of the eigenvalues of the symmetric tensor, which captures the pressure minimum in a plane perpendicular to the vortex axis at high Reynolds numbers, and also accurately defines vortex cores at low Reynolds numbers.
Journal ArticleDOI
The Proper Orthogonal Decomposition in the Analysis of Turbulent Flows
TL;DR: The Navier-Stokes equations are well-known to be a good model for turbulence as discussed by the authors, and the results of well over a century of increasingly sophisticated experiments are available at our disposal.
Journal ArticleDOI
Wavelet Transforms and their Applications to Turbulence
TL;DR: Wavelet transforms are recent mathematical techniques, based on group theory and square integrable representations, which allows one to unfold a signal, or a field, into both space and scale, and possibly directions.
References
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Journal ArticleDOI
Mathematical analysis of random noise
TL;DR: In this paper, the authors used the representations of the noise currents given in Section 2.8 to derive some statistical properties of I(t) and its zeros and maxima.
Journal ArticleDOI
On density effects and large structure in turbulent mixing layers
Garry L. Brown,Anatol Roshko +1 more
TL;DR: In this article, Spark shadow pictures and measurements of density fluctuations suggest that turbulent mixing and entrainment is a process of entanglement on the scale of the large structures; some statistical properties of the latter are used to obtain an estimate of entrainedment rates, and large changes of the density ratio across the mixing layer were found to have a relatively small effect on the spreading angle.
Journal ArticleDOI
Organized Motion in Turbulent Flow
TL;DR: A review of organized motion in turbulent flow indicates that the transport properties of most shear flows are dominated by large-scale vortex nonrandom motions as mentioned in this paper, and the boundary layer coherent structure was isolated by the correlation methods of Townsend (1956) and flow visualization by direct observations of complex unsteady turbulent motions.
Journal ArticleDOI
Finite amplitude cellular convection
W. V. R. Malkus,G. Veronis +1 more
TL;DR: In this paper, a method for determining the form and amplitude of a layer of convection is presented, where the non-linear equations describing the fields of motion and temperature are expanded in a sequence of inhomogeneous linear equations dependent upon the solutions of the linear stability problem.