Documents disponibles écrits par cet auteur

Computational investigations into draining in an axisymmetric vessel / Adam Robinson in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 12 (Décembre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 12 (Décembre 2010) . - 07 p. Titre : Computational investigations into draining in an axisymmetric vessel Type de document : texte imprimé Auteurs : Adam Robinson, Auteur ; Hervé Morvan, Auteur ; Carol Eastwick, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : aerospace  engines;  computational  fluid  dynamics;  machine  bearings;  oils;  pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Within an aero-engine, bearing chamber oil is provided for components to lubricate and cool. This oil must be efficiently removed (scavenged) from the chamber to ensure that it does not overheat and degrade. Bearing chambers typically contain a sump section with an exit pipe leading to a scavenge pump. In this paper, a simplified physical situation related to bearing chamber scavenge is computationally modeled. The volume of fluid (VOF) model of Hirt and Nichols (1981, “Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries,” J. Comput. Phys., 39, pp. 201–225), implemented within the commercial computational fluid dynamics (CFD) code FLUENT (Fluent, 2006, Fluent 6.3 User's Guide, 10 Cavendish Court, Lebanon, NH 03766), has been applied to investigate the case of transient draining in an axisymmetric vessel. The model is setup to match the experimental work of Lubin and Springer (1967, “The Formation of a Dip on the Surface of a Liquid Draining From a Tank,” J. Fluid Mech., 29(2), pp. 385–390). First, a comparison of the computational predictions with the experimental results for free draining is presented. Second, a comparison between the free surface positions obtained the developed VOF methodology and the results obtained by Zhou and Graebel (1990, “Axisymmetric Draining of a Cylindrical Tank With a Free Surface,” J. Fluid Mech., 221, pp. 511–532) using a boundary integral method is reported. When comparing the results with the observations of Lubin and Springer some differences are noted. These differences, which relate to the effect of initial height and outflow history, may have arisen due to the experimental procedure used by Lubin and Springer. This paper shows that CFD is a promising approach to analyzing these simple draining situations in terms of predicting bulk quantities, transitions, and free-surface shape and position. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000132000012 [...] [article] Computational investigations into draining in an axisymmetric vessel [texte imprimé] / Adam Robinson, Auteur ; Hervé Morvan, Auteur ; Carol Eastwick, Auteur . - 2011 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 12 (Décembre 2010) . - 07 p. Mots-clés : aerospace  engines;  computational  fluid  dynamics;  machine  bearings;  oils;  pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Within an aero-engine, bearing chamber oil is provided for components to lubricate and cool. This oil must be efficiently removed (scavenged) from the chamber to ensure that it does not overheat and degrade. Bearing chambers typically contain a sump section with an exit pipe leading to a scavenge pump. In this paper, a simplified physical situation related to bearing chamber scavenge is computationally modeled. The volume of fluid (VOF) model of Hirt and Nichols (1981, “Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries,” J. Comput. Phys., 39, pp. 201–225), implemented within the commercial computational fluid dynamics (CFD) code FLUENT (Fluent, 2006, Fluent 6.3 User's Guide, 10 Cavendish Court, Lebanon, NH 03766), has been applied to investigate the case of transient draining in an axisymmetric vessel. The model is setup to match the experimental work of Lubin and Springer (1967, “The Formation of a Dip on the Surface of a Liquid Draining From a Tank,” J. Fluid Mech., 29(2), pp. 385–390). First, a comparison of the computational predictions with the experimental results for free draining is presented. Second, a comparison between the free surface positions obtained the developed VOF methodology and the results obtained by Zhou and Graebel (1990, “Axisymmetric Draining of a Cylindrical Tank With a Free Surface,” J. Fluid Mech., 221, pp. 511–532) using a boundary integral method is reported. When comparing the results with the observations of Lubin and Springer some differences are noted. These differences, which relate to the effect of initial height and outflow history, may have arisen due to the experimental procedure used by Lubin and Springer. This paper shows that CFD is a promising approach to analyzing these simple draining situations in terms of predicting bulk quantities, transitions, and free-surface shape and position. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000132000012 [...]

The concept of roughness in fluvial hydraulics and its formulation in 1D, 2D and 3D numerical simulation models / Hervé Morvan in Journal of hydraulic research, Vol. 46 N°2 (2008) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 46 N°2 (2008) . - p. 191-208 Titre : The concept of roughness in fluvial hydraulics and its formulation in 1D, 2D and 3D numerical simulation models Titre original : Le concept de rugosité en hydraulique fluviale et sa formulation dans les modèles de simulation numérique 1D, 2D et 3D Type de document : texte imprimé Auteurs : Hervé Morvan, Auteur ; Donald Knight, Auteur ; Nigel Wright, Auteur Article en page(s) : p. 191-208 Note générale : Hydraulique Résumé en Français Langues : Anglais (eng) Mots-clés : Flow  Modeling  Resistance  Rivers  Roughness 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 : This paper gives an overview of the meaning of the term “roughness” in the field of fluvial hydraulics, and how it is often formulated as a “resistance to flow” term in 1D, 2D and 3D numerical models. It looks at how roughness is traditionally characterized in both experimental and numerical fields, and subsequently challenges the definitions that currently exist. In the end, the authors wonder: Is roughness well understood and defined at all? Such a question raises a number of concerns in both research and practice; for example, how does one modeller use the roughness value from an experimental piece of work, or how does a practitioner identify the roughness value of a particular river channel? The authors indicate that roughness may not be uniquely defined, that there may be distinct “experimental” and “numerical” roughness values, and that in each field nuances exist associated with the context in which these values are used. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.journalhydraulicresearch.com [article] The concept of roughness in fluvial hydraulics and its formulation in 1D, 2D and 3D numerical simulation models = Le concept de rugosité en hydraulique fluviale et sa formulation dans les modèles de simulation numérique 1D, 2D et 3D [texte imprimé] / Hervé Morvan, Auteur ; Donald Knight, Auteur ; Nigel Wright, Auteur . - p. 191-208. Hydraulique Résumé en Français Langues : Anglais (eng) in Journal of hydraulic research > Vol. 46 N°2 (2008) . - p. 191-208 Mots-clés : Flow  Modeling  Resistance  Rivers  Roughness 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 : This paper gives an overview of the meaning of the term “roughness” in the field of fluvial hydraulics, and how it is often formulated as a “resistance to flow” term in 1D, 2D and 3D numerical models. It looks at how roughness is traditionally characterized in both experimental and numerical fields, and subsequently challenges the definitions that currently exist. In the end, the authors wonder: Is roughness well understood and defined at all? Such a question raises a number of concerns in both research and practice; for example, how does one modeller use the roughness value from an experimental piece of work, or how does a practitioner identify the roughness value of a particular river channel? The authors indicate that roughness may not be uniquely defined, that there may be distinct “experimental” and “numerical” roughness values, and that in each field nuances exist associated with the context in which these values are used. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.journalhydraulicresearch.com