Local estimates of Hölder exponents in turbulent vector fields

Nguyen, Florian; Laval, Jean-Philippe; Kestener, Pierre; Cheskidov, Alexey; Shvydkoy, Roman; Dubrulle, Bérengère

doi:10.1103/physreve.99.053114

Cited by 13 publications

(18 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2020) and in numerical simulations (Nguyen et al. 2019). This points out the complex dynamics of the small scale structures of turbulence, and calls for further investigation, to determine the role of local energy transfer in the formation of high vorticity zones or the reverse.…”

Section: Discussionmentioning

confidence: 99%

“…(2019) found a different multi-fractal spectrum between the two fields in a numerical simulation at the same but with a large resolution (see figures 7 and 8 in Nguyen et al. (2019)). From the experimental side, Paret & Tabeling (1998) used a simultaneous monitoring of local pressure and velocity in an experimental flow at large Reynolds number to find that the intermittency is decreased when removing from the velocity signal the portions corresponding to very low pressure events (presumably tracing vortex cores).…”

Section: Introductionmentioning

confidence: 94%

“…However, Nguyen et al. (2019) found a different multi-fractal spectrum between the two fields in a numerical simulation at the same but with a large resolution (see figures 7 and 8 in Nguyen et al. (2019)).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the nature of intermittency in a turbulent von Kármán flow

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

See 1 more Smart Citation

On the nature of intermittency in a turbulent von Kármán flow

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…To test whether the differentiation would be possible at all, we estimated a multifractal spectrum that describes the fluctuation of the local regularity of the observed signals. The multifractal spectrum is estimated in terms of wavelet leaders [ 54 ].…”

Section: Methodsmentioning

confidence: 99%

On Entropy of Probability Integral Transformed Time Series

Bajić

Mišić²,

Škorić

et al. 2020

Entropy

View full text Add to dashboard Cite

The goal of this paper is to investigate the changes of entropy estimates when the amplitude distribution of the time series is equalized using the probability integral transformation. The data we analyzed were with known properties—pseudo-random signals with known distributions, mutually coupled using statistical or deterministic methods that include generators of statistically dependent distributions, linear and non-linear transforms, and deterministic chaos. The signal pairs were coupled using a correlation coefficient ranging from zero to one. The dependence of the signal samples is achieved by moving average filter and non-linear equations. The applied coupling methods are checked using statistical tests for correlation. The changes in signal regularity are checked by a multifractal spectrum. The probability integral transformation is then applied to cardiovascular time series—systolic blood pressure and pulse interval—acquired from the laboratory animals and represented the results of entropy estimations. We derived an expression for the reference value of entropy in the probability integral transformed signals. We also experimentally evaluated the reliability of entropy estimates concerning the matching probabilities.

show abstract

“…In a previous paper, we have developed a method to provide an estimate of the local Hölder exponenth(x) using a local statistical method [19]. The scalar field computed using this method is continuous in space and shares the properties of the true Hölder exponent.…”

Section: Tools For Studying Irregular Motionsmentioning

confidence: 99%

Characterizing most irregular small-scale structures in turbulence using local Hölder exponents

2020

Self Cite

View full text Add to dashboard Cite

Two scalar fields characterizing respectively pseudo-Holder exponents and local energy transfers are used to capture the topology and the dynamics of the velocity fields in areas of lesser regularity.The present analysis is conducted using velocity fields from two Direct Numerical Simulations (DNS) of the Navier-Stokes equations in a triply periodic domain. A "typical irregular structure" is obtained by averaging over 213 most irregular events. Such structure is similar to a Burgers vortex, with non-axisymmetric corrections. A possible explanation of such asymmetry is provided by a detailed time-resolved analysis of birth and death of the irregular structures, which shows that they are connected to vortex interactions, possibly vortex reconnection.

show abstract

Local estimates of Hölder exponents in turbulent vector fields

Cited by 13 publications

References 12 publications

On the nature of intermittency in a turbulent von Kármán flow

On the nature of intermittency in a turbulent von Kármán flow

On Entropy of Probability Integral Transformed Time Series

Characterizing most irregular small-scale structures in turbulence using local Hölder exponents

Contact Info

Product

Resources

About