Longitudinal and transverse structure functions in sheared and unsheared wind-tunnel turbulence

Shen, Xiuzhong; Warhaft, Z.

doi:10.1063/1.1421059

Cited by 86 publications

(95 citation statements)

References 24 publications

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“…Consistency with this prediction was concluded in [8] where it was found that ÿ2:1, while slightly larger were seen in other experiments [9]. Surprisingly, the conclusions of a recent paper [7] are at odds with these findings, and no asymmetry between even and odd transverse exponent was observed.…”

Section: P H Y S I C a L R E V I E W L E T T E R S Week Endingcontrasting

confidence: 46%

Small Scale Velocity Jumps in Shear Turbulence

Staicu

Water

2003

Phys. Rev. Lett.

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Section: P H Y S I C a L R E V I E W L E T T E R S Week Endingcontrasting

confidence: 46%

Small Scale Velocity Jumps in Shear Turbulence

Staicu

Water

2003

Phys. Rev. Lett.

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“…In analogy with the observations made in the stationary case 18,[20][21][22][23][24][25][26] we postulate a scaling behavior…”

Section: ͑6͒mentioning

confidence: 84%

The decay of homogeneous anisotropic turbulence

et al. 2003

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Biferale, L.; Boffetta, G.; Celani, A.; Lanotte, A.; Toschi, F.; Vergassola, M. Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. We present the results of a numerical investigation of three-dimensional decaying turbulence with statistically homogeneous and anisotropic initial conditions. We show that at large times, in the inertial range of scales: ͑i͒ isotropic velocity fluctuations decay self-similarly at an algebraic rate which can be obtained by dimensional arguments; ͑ii͒ the ratio of anisotropic to isotropic fluctuations of a given intensity falls off in time as a power law, with an exponent approximately independent of the strength of the fluctuation; ͑iii͒ the decay of anisotropic fluctuations is not self-similar, their statistics becoming more and more intermittent as time elapses. We also investigate the early stages of the decay. The different short-time behavior observed in two experiments differing by the phase organization of their initial conditions gives a new hunch on the degree of universality of small-scale turbulence statistics, i.e., its independence of the conditions at large scales.

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“…The 1941 theory of Kolmogorov [1] is based on the assumption of local isotropy and homogeneity, that is any turbulent flow, independently on the injection mechanism, recovers universal statistical properties, for scales small enough (and far from the boundaries). Indeed, experiments and numerical simulations give strong indications that Eulerian and Lagrangian isotropic/anisotropic small-scales velocity statistics are pretty independent of the large-scale forcing mechanisms [3][4][5][6][7]. Still, we lack a firm understanding for these evidences.…”

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confidence: 99%

Effects of Forcing in Three-Dimensional Turbulent Flows

2004

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We present the results of a numerical investigation of three-dimensional homogeneous and isotropic turbulence, stirred by a random forcing with a power law spectrum, E f (k) ∼ k 3−y . Numerical simulations are performed at different resolutions up to 512 3 . We show that at varying the spectrum slope y, small-scale turbulent fluctuations change from a forcing independent to a forcing dominated statistics. We argue that the critical value separating the two behaviours, in three dimensions, is yc = 4. When the statistics is forcing dominated, for y < yc, we find dimensional scaling, i.e. intermittency is vanishingly small. On the other hand, for y > yc, we find the same anomalous scaling measured in flows forced only at large scales. We connect these results with the issue of universality in turbulent flows.The effects of both external forcing mechanisms and boundary conditions on small-scale turbulent fluctuations have been the subject of many theoretical, numerical and experimental studies [1,2]. The 1941 theory of Kolmogorov [1] is based on the assumption of local isotropy and homogeneity, that is any turbulent flow, independently on the injection mechanism, recovers universal statistical properties, for scales small enough (and far from the boundaries). Indeed, experiments and numerical simulations give strong indications that Eulerian and Lagrangian isotropic/anisotropic small-scales velocity statistics are pretty independent of the large-scale forcing mechanisms [3][4][5][6][7]. Still, we lack a firm understanding for these evidences. From the theoretical point of view, precious hints arise from linear problems, like passive scalar or passively advected magnetic fields. For the class of Kraichnan models [8], anomalous scaling has been shown to be associated to statistically stationary solutions of the unforced equations for correlation functions [9]. Scaling exponents are consequently universal with respect of the injection mechanisms. Concerning non-linear problems, as the Navier-Stokes case, analytical results have been often pursued by means of the Renormalization Group (RG) [10,11]. In the RG framework, turbulence is stirred at all scales by a self-similar Gaussian field, with zero mean and white-noise in time. The two-point correlation function in Fourier space is given byHere 1/k 0 ∼ L is the largest length in the system (infrared cut-off), D 0 is the forcing intensity, P ij (k) is the projector assuring incompressibility and d is the spatial dimension (always assumed to be d = 3 hereafter). The influence of the stirring mechanism at small scales is governed by the value of the slope y. We go from a situation when the forcing has a strong input at all scales, y ∼ 0 originally investigated in [10], to a quasi large-scale forcing when y → ∞. Renormalization Group calculations, based on a y-expansion, predict a power-law energy spec-where η is the viscous scale of the system, and for y ≪ 1. Notice that the Kolmogorov value, E(k) ∼ k −5/3 , describing experimental turbulent flows stirred by a largescale fo...

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Longitudinal and transverse structure functions in sheared and unsheared wind-tunnel turbulence

Cited by 86 publications

References 24 publications

Small Scale Velocity Jumps in Shear Turbulence

Small Scale Velocity Jumps in Shear Turbulence

The decay of homogeneous anisotropic turbulence

Effects of Forcing in Three-Dimensional Turbulent Flows

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