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On self-similarity in the inner wall layer of a turbulent channel flow / Bérengère Podvin in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 4 (Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 4 (Avril 2010) . - 15 p. Titre : On self-similarity in the inner wall layer of a turbulent channel flow Type de document : texte imprimé Auteurs : Bérengère Podvin, Auteur ; Yann Fraigneau, Auteur ; Julien Jouanguy, Auteur Année de publication : 2010 Article en page(s) : 15 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : flow  (dynamics);  turbulence;  eddies  (fluid  dynamics);  computer  simulation;  Reynolds  number;  polishing  equipment;  eigenfunctions;  channel  flow Résumé : We use proper orthogonal decomposition (POD) to estimate the flow in the near-wall region based on information from the outer buffer layer. Our goal is to assess how the flow structures in the inner wall region are connected to those further away from the wall, and to investigate the nature of the coupling between the inner and the outer region in the POD framework. Reconstructions are carried out for numerical simulations of a plane channel flow at two different Reynolds numbers. We show that elongated structures with a spanwise wavelength smaller than a critical value tend to be concentrated in the inner layer. The critical wavelength is shown to scale with the inner layer height, and interactions between the inner and the outer layer appear to take place predominantly over a self-similar, height-dependent, range of wavenumbers, in agreement with Townsend’s attached eddy hypothesis. The reconstructed field appears to capture an adequate energy content and to remain correlated with the real field even close to the wall, which reflects the persistence of energetic structures over the extent of the buffer layer. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] On self-similarity in the inner wall layer of a turbulent channel flow [texte imprimé] / Bérengère Podvin, Auteur ; Yann Fraigneau, Auteur ; Julien Jouanguy, Auteur . - 2010 . - 15 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 4 (Avril 2010) . - 15 p. Mots-clés : flow  (dynamics);  turbulence;  eddies  (fluid  dynamics);  computer  simulation;  Reynolds  number;  polishing  equipment;  eigenfunctions;  channel  flow Résumé : We use proper orthogonal decomposition (POD) to estimate the flow in the near-wall region based on information from the outer buffer layer. Our goal is to assess how the flow structures in the inner wall region are connected to those further away from the wall, and to investigate the nature of the coupling between the inner and the outer region in the POD framework. Reconstructions are carried out for numerical simulations of a plane channel flow at two different Reynolds numbers. We show that elongated structures with a spanwise wavelength smaller than a critical value tend to be concentrated in the inner layer. The critical wavelength is shown to scale with the inner layer height, and interactions between the inner and the outer layer appear to take place predominantly over a self-similar, height-dependent, range of wavenumbers, in agreement with Townsend’s attached eddy hypothesis. The reconstructed field appears to capture an adequate energy content and to remain correlated with the real field even close to the wall, which reflects the persistence of energetic structures over the extent of the buffer layer. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]