Documents disponibles écrits par cet auteur

Effects of hydraulic jump location on air entrainment in closed conduits / Joshua D. Mortensen in Journal of hydraulic research, Vol. 50 N° 3 (Mai/Juin 2012) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 50 N° 3 (Mai/Juin 2012) . - pp. 298-303 Titre : Effects of hydraulic jump location on air entrainment in closed conduits Type de document : texte imprimé Auteurs : Joshua D. Mortensen, Auteur ; Steven L. Barfuss, Auteur ; Blake P. Tullis, Auteur Année de publication : 2012 Article en page(s) : pp. 298-303 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Air  entrainment  Characteristic  length  Closed  conduit  Hydraulic  jump  Location  effect Résumé : In vented closed conduit conveyance systems, air entrained through hydraulic jumps can be problematic for system operation. While various factors influencing air entrainment have been reported in the literature, no specific attention has been paid to the hydraulic jump location relative to the point of downstream air release. To better understand the effects of jump location on air entrainment, in this study, experiments were conducted in a vented, circular conduit with variable hydraulic jump locations relative to the pipe outlet. When the hydraulic jump was fully contained within the pipe, the air entrainment rate was dependent on the Froude number immediately upstream of the jump but was independent of the jump location within the pipe. The rate of air entrainment significantly increased, however, when the hydraulic jump was not fully contained within the pipe. For this condition, the distance from the toe of the jump to the pipe outlet significantly influences the air entrainment rate. ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/full/10.1080/00221686.2012.670008 [article] Effects of hydraulic jump location on air entrainment in closed conduits [texte imprimé] / Joshua D. Mortensen, Auteur ; Steven L. Barfuss, Auteur ; Blake P. Tullis, Auteur . - 2012 . - pp. 298-303. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 50 N° 3 (Mai/Juin 2012) . - pp. 298-303 Mots-clés : Air  entrainment  Characteristic  length  Closed  conduit  Hydraulic  jump  Location  effect Résumé : In vented closed conduit conveyance systems, air entrained through hydraulic jumps can be problematic for system operation. While various factors influencing air entrainment have been reported in the literature, no specific attention has been paid to the hydraulic jump location relative to the point of downstream air release. To better understand the effects of jump location on air entrainment, in this study, experiments were conducted in a vented, circular conduit with variable hydraulic jump locations relative to the pipe outlet. When the hydraulic jump was fully contained within the pipe, the air entrainment rate was dependent on the Froude number immediately upstream of the jump but was independent of the jump location within the pipe. The rate of air entrainment significantly increased, however, when the hydraulic jump was not fully contained within the pipe. For this condition, the distance from the toe of the jump to the pipe outlet significantly influences the air entrainment rate. ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/full/10.1080/00221686.2012.670008

Scale effects of air entrained by hydraulic jumps within closed conduits / Joshua D. Mortensen in Journal of hydraulic research, Vol. 49 N° 1 (Janvier/Fevrier 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 1 (Janvier/Fevrier 2011) . - pp. 90-95 Titre : Scale effects of air entrained by hydraulic jumps within closed conduits Type de document : texte imprimé Auteurs : Joshua D. Mortensen, Auteur ; Steven L. Barfuss, Auteur ; Michael C. Johnson, Auteur Année de publication : 2011 Article en page(s) : pp. 90-95 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Air  entrainment  Closed  conduit  Hydraulic  jump  Scale  effect  Temperature  effect Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : While there has been a great deal of research in air entrainment at hydraulic jumps within closed conduits, limited research has specifically addressed size-scale effects. To determine the significance of these effects in closed conduits, air flow measurements were taken in four different-sized circular pipes with similar Froude numbers. Additionally, specific measurements were taken in one of the pipes with various water temperatures to identify any effects from changing fluid properties. The results indicated that the percentage of air entrainment was not affected by the pipe size if the full length of the hydraulic jump was contained within the pipe. For this condition, the data from four different pipes show that size-scale effects of air entrained into hydraulic jumps within closed conduits are negligible. However, air entrainment was significantly affected by water temperature. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.informaworld.com/smpp/content~db=all~content=a933339566~frm=titlelink [article] Scale effects of air entrained by hydraulic jumps within closed conduits [texte imprimé] / Joshua D. Mortensen, Auteur ; Steven L. Barfuss, Auteur ; Michael C. Johnson, Auteur . - 2011 . - pp. 90-95. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 1 (Janvier/Fevrier 2011) . - pp. 90-95 Mots-clés : Air  entrainment  Closed  conduit  Hydraulic  jump  Scale  effect  Temperature  effect Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : While there has been a great deal of research in air entrainment at hydraulic jumps within closed conduits, limited research has specifically addressed size-scale effects. To determine the significance of these effects in closed conduits, air flow measurements were taken in four different-sized circular pipes with similar Froude numbers. Additionally, specific measurements were taken in one of the pipes with various water temperatures to identify any effects from changing fluid properties. The results indicated that the percentage of air entrainment was not affected by the pipe size if the full length of the hydraulic jump was contained within the pipe. For this condition, the data from four different pipes show that size-scale effects of air entrained into hydraulic jumps within closed conduits are negligible. However, air entrainment was significantly affected by water temperature. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.informaworld.com/smpp/content~db=all~content=a933339566~frm=titlelink