| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Automatic dynamic mask extraction for PIV images containing an unsteady interface, bubbles, and a moving structure
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| Autores: |
Dussol, David
Druault, Philippe
Mallat, Bachar
Delacroix, Sylvain
Germain, Gregory
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| Data: |
2016-07
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| Ano: |
2016
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| Palavras-chave: |
Particle image velocimetry
Unsteady free interface
Edge detection method
Morphological analysis
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| Resumo: |
When performing Particle Image Velocimetry (PIV) measurements in complex fluid flows with moving interfaces and a two-phase flow, it is necessary to develop a mask to remove non-physical measurements. This is the case when studying, for example, the complex bubble sweep-down phenomenon observed in oceanographic research vessels. Indeed, in such a configuration, the presence of an unsteady free surface, of a solid–liquid interface and of bubbles in the PIV frame, leads to generate numerous laser reflections and therefore spurious velocity vectors. In this note, an image masking process is developed to successively identify the boundaries of the ship and the free surface interface. As the presence of the solid hull surface induces laser reflections, the hull edge contours are simply detected in the first PIV frame and dynamically estimated for consecutive ones. As for the unsteady surface determination, a specific process is implemented like the following: i) the edge detection of the gradient magnitude in the PIV frame, ii) the extraction of the particles by filtering high-intensity large areas related to the bubbles and/or hull reflections, iii) the extraction of the rough region containing these particles and their reflections, iv) the removal of these reflections. The unsteady surface is finally obtained with a fifth-order polynomial interpolation. The resulted free surface is successfully validated from the Fourier analysis and by visualizing selected PIV images containing numerous spurious high intensity areas. This paper demonstrates how this data analysis process leads to PIV images database without reflections and an automatic detection of both the free surface and the rigid body. An application of this new mask is finally detailed, allowing a preliminary analysis of the hydrodynamic flow.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
http://archimer.ifremer.fr/doc/00327/43778/43335.pdf
DOI:10.1016/j.crme.2016.03.005
http://archimer.ifremer.fr/doc/00327/43778/
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| Editor: |
Elsevier France-editions Scientifiques Medicales Elsevier
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| Formato: |
application/pdf
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| Fonte: |
Comptes Rendus Mecanique (1631-0721) (Elsevier France-editions Scientifiques Medicales Elsevier), 2016-07 , Vol. 344 , N. 7 , P. 464-478
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| Direitos: |
2016 Académie des sciences. Published by Elsevier Masson SAS. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
info:eu-repo/semantics/openAccess
restricted use
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