Extraction of coherent structure from PIV data using wavelet transform

Hitoshi Miyamoto, Tohru Kanda

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Velocity fields measured by a particle image velocimetry (PIV) are analyzed by using the wavelet transform. Considered here are coherent structures in the mixing layer of turbulent open-channel flow over a concave bed. At first, we examine the capability of the continuous wavelet transform (CWT) for the coherent structure detection. By applying CWT to an instantaneous velocity distribution measured by PIV, the locations and spatial scales of the coherent structures along the mixing layer have been successfully obtained from the locations of the extremal values of wavelet coefficient in the space-wavenumber domain. Then, a conditional sampling is used to extract the locations and the respective spatial scales for the maximal values of the wavelet coefficient in each time step. Consequently, the characteristics of the coherent structures along the mixing layer, such as the evolution of the spatial scale, advection velocity, and occurrence interval, are clearly illustrated as functions of the location and the time. Furthermore, by applying CWT to the time series of the velocities in each location of the channel instead of the velocity distribution, the frequencies of the coherent structures are found out in addition to the above characteristics. The joint probability distribution of the spatial scale and the frequency shows that there is a linear relationship between them. These results strongly suggest that the wavelet transform is a useful tool for extracting the coherent structures embedded on the velocities obtained by PIV measurement. Copyright ASCE 2004.

Original languageEnglish
Title of host publicationJoint Conference on Water Resource Engineering and Water Resources Planning and Management 2000
Subtitle of host publicationBuilding Partnerships
DOIs
Publication statusPublished - 2004 Dec 1
Externally publishedYes
EventJoint Conference on Water Resource Engineering and Water Resources Planning and Management 2000 - Minneapolis, MN, United States
Duration: 2000 Jul 302000 Aug 2

Publication series

NameJoint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships
Volume104

Conference

ConferenceJoint Conference on Water Resource Engineering and Water Resources Planning and Management 2000
CountryUnited States
CityMinneapolis, MN
Period00/7/3000/8/2

Keywords

  • Coherent structure
  • Concave bed
  • Open-channel flow
  • Particle image velocimetry
  • Wavelet transform

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Water Science and Technology
  • Geography, Planning and Development

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  • Cite this

    Miyamoto, H., & Kanda, T. (2004). Extraction of coherent structure from PIV data using wavelet transform. In Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships (Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships; Vol. 104). https://doi.org/10.1061/40517(2000)326