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Extraction of 3D vortex structures from a turbulent puff in a pipe using two-color illumination and flakes
| Title: | Extraction of 3D vortex structures from a turbulent puff in a pipe using two-color illumination and flakes |
| Authors: | Ohkubo, Jumpei Browse this author | | Tasaka, Yuji Browse this author →KAKEN DB | | Park, Hyun Jin Browse this author | | Murai, Yuichi Browse this author →KAKEN DB |
| Keywords: | Pipe flow | | Turbulence transition | | Flow visualization | | Flake |
| Issue Date: | Nov-2016 |
| Publisher: | Springer |
| Journal Title: | Journal of visualization |
| Volume: | 19 |
| Issue: | 4 |
| Start Page: | 643 |
| End Page: | 651 |
| Publisher DOI: | 10.1007/s12650-016-0344-z |
| Abstract: | A novel visualization technique was proposed to extract the three-dimensional vortex structure of a turbulent puff, which is a local turbulence event that is observed in pipe flows at relatively low Reynolds numbers. The technique is based on multi-color illumination of microscopic flakes that are suspended in the flow, which makes structural visualization more informative than conventional monochrome approaches. A special optical arrangement of two laser sheets, colored green and blue, was established for the circular pipe. Based on an image analysis sequence, the internal structure of the puff is reconstructed as a cross-sectional temporal 3D image consisting of voxels with unicolor degrees between green and blue, where an individual single vortex is extracted as a pair of two-color stripes. This allows quantification of the azimuthal wavenumber of the vortical structure that characterizes the puff. The wavenumber results agreed well with the results of previous studies, thus supporting the applicability of the proposed visualization technique. . |
| Rights: | The original publication is available at www.springerlink.com |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/67494 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 田坂 裕司
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