PIV algorithms for open-channel turbulence research

accuracy, resolution and limitations

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The implementation of PIV for experimental studies in open-channel flows can be challenging due to the presence of strong velocity gradients and the inclusion of solid interfaces in the captured images. Understanding the performance and limitations of the PIV method under these conditions is critical for optimising experimental parameters and robust interpretation of data. The optimum algorithm for extracting velocity fields from PIV images is the subject of ongoing revision with the goal of maximising resolution and minimising errors, and recent advances in this regard may be particularly beneficial for open-channel turbulence research. Key steps in the iterative discrete shift (IDS) and image deformation method (IDM) algorithms are detailed, and the fundamental differences between direct cross correlation and FFT-based correlation methods are explained. It is also shown how the resolution of an algorithm can be determined from its modulation transfer function (MTF), and how the MTF can be manipulated with the selection of intensity weighting windows. The random error levels for selected algorithms are demonstrated under different image and flow field conditions, including the near boundary region, using simulated PIV images.
Original languageEnglish
Pages (from-to)247-262
Number of pages16
JournalJournal of Hydro-Environment Research
Volume5
Issue number4
DOIs
Publication statusPublished - Dec 2011

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Turbulence
turbulence
Optical transfer function
transfer function
Open channel flow
Random errors
Correlation methods
open channel flow
Fast Fourier transforms
Flow fields
flow field
experimental study
method

Keywords

  • particle image velocimetry
  • resolution
  • error
  • accuracy

Cite this

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