### Abstract

This study focuses on the distribution of time scales and its relation to integral time scales in non-Gaussian turbulence within plant canopies. We introduce the idea of persistence usually used to describe nonequilibrium systems to the analysis of time series of turbulence as a simple approach to characterize the distribution of time scales. Analysis of turbulence data within and above a cornfield shows that the integral time scale is not adequate to characterize the duration of long events in non-Gaussian turbulence. Positive and negative events have different time scales as a consequence of the skewness of the velocity fluctuations. Sweeps (u' > 0 and w' < 0) are stronger and have shorter durations, and dominate the behavior of the integral time scale. At the same time, ejections (u' < 0 and w' > 0) tend to be much longer lived, and their signature (which is not clearly seen in the integral time scale) is clearly identified in the distributions of persistence time.

Original language | English (US) |
---|---|

Article number | 115110 |

Journal | Physics of Fluids |

Volume | 25 |

Issue number | 11 |

DOIs | |

State | Published - Aug 30 2013 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Condensed Matter Physics

### Cite this

*Physics of Fluids*,

*25*(11), [115110]. https://doi.org/10.1063/1.4832955

}

*Physics of Fluids*, vol. 25, no. 11, 115110. https://doi.org/10.1063/1.4832955

**Persistence of velocity fluctuations in non-Gaussian turbulence within and above plant canopies.** / Chamecki, Marcelo.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Persistence of velocity fluctuations in non-Gaussian turbulence within and above plant canopies

AU - Chamecki, Marcelo

PY - 2013/8/30

Y1 - 2013/8/30

N2 - This study focuses on the distribution of time scales and its relation to integral time scales in non-Gaussian turbulence within plant canopies. We introduce the idea of persistence usually used to describe nonequilibrium systems to the analysis of time series of turbulence as a simple approach to characterize the distribution of time scales. Analysis of turbulence data within and above a cornfield shows that the integral time scale is not adequate to characterize the duration of long events in non-Gaussian turbulence. Positive and negative events have different time scales as a consequence of the skewness of the velocity fluctuations. Sweeps (u' > 0 and w' < 0) are stronger and have shorter durations, and dominate the behavior of the integral time scale. At the same time, ejections (u' < 0 and w' > 0) tend to be much longer lived, and their signature (which is not clearly seen in the integral time scale) is clearly identified in the distributions of persistence time.

AB - This study focuses on the distribution of time scales and its relation to integral time scales in non-Gaussian turbulence within plant canopies. We introduce the idea of persistence usually used to describe nonequilibrium systems to the analysis of time series of turbulence as a simple approach to characterize the distribution of time scales. Analysis of turbulence data within and above a cornfield shows that the integral time scale is not adequate to characterize the duration of long events in non-Gaussian turbulence. Positive and negative events have different time scales as a consequence of the skewness of the velocity fluctuations. Sweeps (u' > 0 and w' < 0) are stronger and have shorter durations, and dominate the behavior of the integral time scale. At the same time, ejections (u' < 0 and w' > 0) tend to be much longer lived, and their signature (which is not clearly seen in the integral time scale) is clearly identified in the distributions of persistence time.

UR - http://www.scopus.com/inward/record.url?scp=84888807134&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84888807134&partnerID=8YFLogxK

U2 - 10.1063/1.4832955

DO - 10.1063/1.4832955

M3 - Article

AN - SCOPUS:84888807134

VL - 25

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 11

M1 - 115110

ER -