Extension of POD analysis toward the three-dimensional coherent structure

R. Gurka*, A. Liberzon, G. Hetsroni

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


We summarize in this contribution our quest toward characterization of a 3D coherent structure. The study started with the microbubble flow visualization experiments of Gad Hetsroni and his co-authors back in the 1990s and expanded during 1999-2003 study using particle image velocimetry (PIV) and proper orthogonal decomposition (POD). The topology of large scale structures in the turbulent boundary layer in a flume is investigated experimentally. The 2D velocity fields are obtained by a stereoscopic PIV system that enables to measure out-of-plane velocity components. The large scale structure is reconstructed from the POD modes of vorticity in three orthogonal planes. Extending on the previous studies, the dominant coherent pattern is visualized in 3D, combining the three orthogonal projections. The pattern appears as a streamwise oriented vortex structure of length of ≈ 1000 wall units and with the inclination angle of ≈ 9 °. The proposed POD-based characterization method leads to a conceptual illustration of a 3D structure. The shape resembles the "funnel" structure proposed by Prof. Hetsroni and colleagues in 1990s based on the microbubble flow visualization images.

Original languageEnglish
Title of host publicationMultiphase Flow Phenomena and Applications
Subtitle of host publicationMemorial Volume in Honor of Gad Hetsroni
PublisherWorld Scientific Publishing Co. Pte Ltd
Number of pages12
ISBN (Electronic)9789813227392
ISBN (Print)9789813227385
StatePublished - 8 Feb 2018
EventInternational Conference on Multiphase Flow 2016 - Firenze, Italy
Duration: 22 May 201627 May 2016
Conference number: 9


ConferenceInternational Conference on Multiphase Flow 2016
Abbreviated titleICMF-16
City Firenze
Internet address


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