Characterisation of the Eulerian and Lagrangian accelerations in the intermediate field of turbulent circular jets

J. T. Kim, A. Liberzon, L. P. Chamorro

Research output: Contribution to journalArticle

Abstract

A rich data-set of Lagrangian trajectories from 3D particle tracking velocimetry is used to study the structure of various acceleration components, vorticity, and strain in the intermediate field of a circular jet at Reynolds number Re = 6000. The total acceleration is decomposed into three distinctive sets: (1) streamwise–radial; (2) tangential–normal; and (3) local–convective components. Probability density function (PDF) and joint distributions of each set are characterised at various radial locations from the jet core within a streamwise band 16 ≤ x/dh ≤ 17, where dh is the diameter of the pipe. The PDF of the relative angle between the acceleration components and the velocity vector is also included to aid the characterisation. Results show that the acceleration components are described by two distinctive distributions: one of them exhibits symmetry and heavy tails, while the other is best fitted by a power-law type. The tails of acceleration PDFs are heavier with larger radial distance from the core. The increased departure from the Gaussian distribution with the distance from the core is a result of the increasing turbulence levels promoted by the mean shear. The variation of the third and fourth moments between the streamwise–tangential and the radial–normal accelerations indicate the anisotropy of the jet. Joint PDF of each acceleration decomposition exhibits distinctive distribution that appears to depend from the distance from the jet core. However, the vorticity and strain show similar PDF across radial distances. Finally, complementary analysis of a jet from a semicircular pipe shows the footprint of the nozzle geometry in the acceleration structure of jets.

Original languageEnglish (US)
Pages (from-to)87-102
Number of pages16
JournalJournal of Turbulence
Volume18
Issue number1
DOIs
StatePublished - Jan 2 2017

Fingerprint

probability density functions
Probability density function
Vorticity
vorticity
Pipe
nozzle geometry
Gaussian distribution
footprints
normal density functions
Velocity measurement
Nozzles
Reynolds number
Anisotropy
Turbulence
turbulence
Trajectories
trajectories
shear
Decomposition
moments

Keywords

  • Acceleration
  • Lagrangian description
  • circular jets
  • particle tracking velocimetry
  • turbulence

ASJC Scopus subject areas

  • Computational Mechanics
  • Condensed Matter Physics
  • Mechanics of Materials
  • Physics and Astronomy(all)

Cite this

Characterisation of the Eulerian and Lagrangian accelerations in the intermediate field of turbulent circular jets. / Kim, J. T.; Liberzon, A.; Chamorro, L. P.

In: Journal of Turbulence, Vol. 18, No. 1, 02.01.2017, p. 87-102.

Research output: Contribution to journalArticle

@article{f85cbcae250e42f0a17398206d2248e9,
title = "Characterisation of the Eulerian and Lagrangian accelerations in the intermediate field of turbulent circular jets",
abstract = "A rich data-set of Lagrangian trajectories from 3D particle tracking velocimetry is used to study the structure of various acceleration components, vorticity, and strain in the intermediate field of a circular jet at Reynolds number Re = 6000. The total acceleration is decomposed into three distinctive sets: (1) streamwise–radial; (2) tangential–normal; and (3) local–convective components. Probability density function (PDF) and joint distributions of each set are characterised at various radial locations from the jet core within a streamwise band 16 ≤ x/dh ≤ 17, where dh is the diameter of the pipe. The PDF of the relative angle between the acceleration components and the velocity vector is also included to aid the characterisation. Results show that the acceleration components are described by two distinctive distributions: one of them exhibits symmetry and heavy tails, while the other is best fitted by a power-law type. The tails of acceleration PDFs are heavier with larger radial distance from the core. The increased departure from the Gaussian distribution with the distance from the core is a result of the increasing turbulence levels promoted by the mean shear. The variation of the third and fourth moments between the streamwise–tangential and the radial–normal accelerations indicate the anisotropy of the jet. Joint PDF of each acceleration decomposition exhibits distinctive distribution that appears to depend from the distance from the jet core. However, the vorticity and strain show similar PDF across radial distances. Finally, complementary analysis of a jet from a semicircular pipe shows the footprint of the nozzle geometry in the acceleration structure of jets.",
keywords = "Acceleration, Lagrangian description, circular jets, particle tracking velocimetry, turbulence",
author = "Kim, {J. T.} and A. Liberzon and Chamorro, {L. P.}",
year = "2017",
month = "1",
day = "2",
doi = "10.1080/14685248.2016.1256483",
language = "English (US)",
volume = "18",
pages = "87--102",
journal = "Journal of Turbulence",
issn = "1468-5248",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Characterisation of the Eulerian and Lagrangian accelerations in the intermediate field of turbulent circular jets

AU - Kim, J. T.

AU - Liberzon, A.

AU - Chamorro, L. P.

PY - 2017/1/2

Y1 - 2017/1/2

N2 - A rich data-set of Lagrangian trajectories from 3D particle tracking velocimetry is used to study the structure of various acceleration components, vorticity, and strain in the intermediate field of a circular jet at Reynolds number Re = 6000. The total acceleration is decomposed into three distinctive sets: (1) streamwise–radial; (2) tangential–normal; and (3) local–convective components. Probability density function (PDF) and joint distributions of each set are characterised at various radial locations from the jet core within a streamwise band 16 ≤ x/dh ≤ 17, where dh is the diameter of the pipe. The PDF of the relative angle between the acceleration components and the velocity vector is also included to aid the characterisation. Results show that the acceleration components are described by two distinctive distributions: one of them exhibits symmetry and heavy tails, while the other is best fitted by a power-law type. The tails of acceleration PDFs are heavier with larger radial distance from the core. The increased departure from the Gaussian distribution with the distance from the core is a result of the increasing turbulence levels promoted by the mean shear. The variation of the third and fourth moments between the streamwise–tangential and the radial–normal accelerations indicate the anisotropy of the jet. Joint PDF of each acceleration decomposition exhibits distinctive distribution that appears to depend from the distance from the jet core. However, the vorticity and strain show similar PDF across radial distances. Finally, complementary analysis of a jet from a semicircular pipe shows the footprint of the nozzle geometry in the acceleration structure of jets.

AB - A rich data-set of Lagrangian trajectories from 3D particle tracking velocimetry is used to study the structure of various acceleration components, vorticity, and strain in the intermediate field of a circular jet at Reynolds number Re = 6000. The total acceleration is decomposed into three distinctive sets: (1) streamwise–radial; (2) tangential–normal; and (3) local–convective components. Probability density function (PDF) and joint distributions of each set are characterised at various radial locations from the jet core within a streamwise band 16 ≤ x/dh ≤ 17, where dh is the diameter of the pipe. The PDF of the relative angle between the acceleration components and the velocity vector is also included to aid the characterisation. Results show that the acceleration components are described by two distinctive distributions: one of them exhibits symmetry and heavy tails, while the other is best fitted by a power-law type. The tails of acceleration PDFs are heavier with larger radial distance from the core. The increased departure from the Gaussian distribution with the distance from the core is a result of the increasing turbulence levels promoted by the mean shear. The variation of the third and fourth moments between the streamwise–tangential and the radial–normal accelerations indicate the anisotropy of the jet. Joint PDF of each acceleration decomposition exhibits distinctive distribution that appears to depend from the distance from the jet core. However, the vorticity and strain show similar PDF across radial distances. Finally, complementary analysis of a jet from a semicircular pipe shows the footprint of the nozzle geometry in the acceleration structure of jets.

KW - Acceleration

KW - Lagrangian description

KW - circular jets

KW - particle tracking velocimetry

KW - turbulence

UR - http://www.scopus.com/inward/record.url?scp=84995388225&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84995388225&partnerID=8YFLogxK

U2 - 10.1080/14685248.2016.1256483

DO - 10.1080/14685248.2016.1256483

M3 - Article

AN - SCOPUS:84995388225

VL - 18

SP - 87

EP - 102

JO - Journal of Turbulence

JF - Journal of Turbulence

SN - 1468-5248

IS - 1

ER -