Documents disponibles écrits par cet auteur

Vortex breakdown in an enclosed cylinder with a partially rotating bottom-wall / P. Yu in Transactions of the ASME . Journal of fluids engineering, Vol. 130 N° 11 (Novembre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 11 (Novembre 2008) . - 12 p. Titre : Vortex breakdown in an enclosed cylinder with a partially rotating bottom-wall Type de document : texte imprimé Auteurs : P. Yu, Auteur ; T. S. Lee, Auteur ; Y. Zeng, Auteur Année de publication : 2009 Article en page(s) : 12 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Vortices;  cylinders;  angular  momentum;  flow  (Dynamics);  Reynolds  number;  disks Résumé : A numerical study of the axisymmetric flow in a cylindrical chamber of height H is presented, which is driven by a bottom disk rotating at angular velocity Ω. However, unlike most previous studies, the present rotating disk is of smaller radius than the bottom-wall. The boundary curves for the onset of vortex breakdown are presented using different definitions of the nondimensional parameters, depending on whether the cylinder radius R or the disk radius rd is used as the length scale. The study shows that the boundary curves are best correlated when presented in terms of the Reynolds number Ωrd2∕υ, aspect ratio H∕R, and cylinder-to-disk ratio R∕rd. The cylinder-to-disk ratio R∕rd up to 1.6 is found to have noticeable effect on vortex breakdown; this is attributed to the change of effective aspect ratio. The contours of streamline, angular momentum, and azimuthal vorticity are presented and compared with those of whole bottom-wall rotation. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Vortex breakdown in an enclosed cylinder with a partially rotating bottom-wall [texte imprimé] / P. Yu, Auteur ; T. S. Lee, Auteur ; Y. Zeng, Auteur . - 2009 . - 12 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 11 (Novembre 2008) . - 12 p. Mots-clés : Vortices;  cylinders;  angular  momentum;  flow  (Dynamics);  Reynolds  number;  disks Résumé : A numerical study of the axisymmetric flow in a cylindrical chamber of height H is presented, which is driven by a bottom disk rotating at angular velocity Ω. However, unlike most previous studies, the present rotating disk is of smaller radius than the bottom-wall. The boundary curves for the onset of vortex breakdown are presented using different definitions of the nondimensional parameters, depending on whether the cylinder radius R or the disk radius rd is used as the length scale. The study shows that the boundary curves are best correlated when presented in terms of the Reynolds number Ωrd2∕υ, aspect ratio H∕R, and cylinder-to-disk ratio R∕rd. The cylinder-to-disk ratio R∕rd up to 1.6 is found to have noticeable effect on vortex breakdown; this is attributed to the change of effective aspect ratio. The contours of streamline, angular momentum, and azimuthal vorticity are presented and compared with those of whole bottom-wall rotation. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]