Accuracy of tomographic particle image velocimetry data on a turbulent round jet

M. Khashehchi, Zambri Harun

Research output: Contribution to journalArticle

Abstract

Tomographic particle image velocimetry (Tomo-PIV) was applied on a turbulent round air jet to quantitatively assess the accuracy of velocity gradients obtained in the self-similar turbulent region. The jet Reynolds number based on the nozzle diameter (d) was Re d = 3000. Mean velocity, turbulent intensities, and Reynolds shear stress at the center plane of the jet were measured. In addition, statistical results of Tomo-PIV along the axial direction were assessed by performing a separate set of two-dimensional two-component PIV experiments on a “side view” plane along the jet axis. Moreover, the probability distribution functions of four components of the measured velocity gradients in the axial and radial directions were validated by these “side view” planar PIV data. The root mean square of the velocity divergence values relative to the norm of the velocity gradient tensor was 0.36. Furthermore, the on- and off-diagonal components of the velocity gradients satisfied the axisymmetric isotropy conditions. The divergence error in the data affected only areas with low gradient magnitude. Therefore, turbulent structures in the regions with intense vorticity and dissipation can be closely monitored. On this basis, the joint pdfs of the invariants of the velocity gradient and strain and rotation tensor rates were produced and compared well with those in isotropic turbulence studies.

Original languageEnglish
Pages (from-to)61-72
Number of pages12
JournalInternational Journal of Heat and Fluid Flow
Volume77
DOIs
Publication statusPublished - 1 Jun 2019

Fingerprint

particle image velocimetry
Velocity measurement
gradients
Tensors
divergence
tensors
air jets
isotropic turbulence
probability distribution functions
Reynolds stress
isotropy
Vorticity
norms
vorticity
Probability distributions
shear stress
nozzles
Distribution functions
Shear stress
Nozzles

Keywords

  • Planar PIV
  • Round turbulent jet
  • Tomographic Particle Image Velocimetry
  • VGT

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this

Accuracy of tomographic particle image velocimetry data on a turbulent round jet. / Khashehchi, M.; Harun, Zambri.

In: International Journal of Heat and Fluid Flow, Vol. 77, 01.06.2019, p. 61-72.

Research output: Contribution to journalArticle

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