Documents disponibles écrits par cet auteur

A numerical study of friction in isothermal EHD rolling-sliding sphere-plane contacts with spinning / H. Dormois in Transactions of the ASME . Journal of tribology, Vol. 132 N° 2 (Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 10 p. Titre : A numerical study of friction in isothermal EHD rolling-sliding sphere-plane contacts with spinning Type de document : texte imprimé Auteurs : H. Dormois, Auteur ; N. Fillot, Auteur ; W. Habchi, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Electrohydrodynamics  Finite  element  analysis  Internal  stresses  Point  contacts  Rolling  friction  Sliding  friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents a study of the spinning influence on film thickness and friction in EHL circular contacts under isothermal and fully flooded conditions. Pressure and film thickness profiles are computed with an original full-system finite element approach. Friction was thereafter investigated with the help of a classical Ree–Eyring model to calculate the longitudinal and transverse shear stresses. An analysis of both the velocity and shear stress distributions at every point of the contact surfaces has allowed explaining the fall of the longitudinal friction coefficient due to the occurrence of opposite shear stresses over the contact area. Moreover in the transverse direction spinning favors large shear stresses of opposite signs, decreasing the fluid viscosity by non-Newtonian effects. These effects have direct and coupled consequences on the friction reduction that is observed in the presence of spinning. They are expected to further decrease friction in real situations due to shear heating. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A numerical study of friction in isothermal EHD rolling-sliding sphere-plane contacts with spinning [texte imprimé] / H. Dormois, Auteur ; N. Fillot, Auteur ; W. Habchi, Auteur . - 2011 . - 10 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 10 p. Mots-clés : Electrohydrodynamics  Finite  element  analysis  Internal  stresses  Point  contacts  Rolling  friction  Sliding  friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents a study of the spinning influence on film thickness and friction in EHL circular contacts under isothermal and fully flooded conditions. Pressure and film thickness profiles are computed with an original full-system finite element approach. Friction was thereafter investigated with the help of a classical Ree–Eyring model to calculate the longitudinal and transverse shear stresses. An analysis of both the velocity and shear stress distributions at every point of the contact surfaces has allowed explaining the fall of the longitudinal friction coefficient due to the occurrence of opposite shear stresses over the contact area. Moreover in the transverse direction spinning favors large shear stresses of opposite signs, decreasing the fluid viscosity by non-Newtonian effects. These effects have direct and coupled consequences on the friction reduction that is observed in the presence of spinning. They are expected to further decrease friction in real situations due to shear heating. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]

A two-phase flow approach for the outlet of lubricated line contacts / V. Bruyere in Transactions of the ASME . Journal of tribology, Vol. 134 N° 04 (Octobre 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 134 N° 04 (Octobre 2012) . - 10 p. Titre : A two-phase flow approach for the outlet of lubricated line contacts Type de document : texte imprimé Auteurs : V. Bruyere, Auteur ; N. Fillot, Auteur ; G. E. Morales-Espejel, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : tribology Langues : Anglais (eng) Mots-clés : hydrodynamic  lubrication;  two-phase  flow;  Navier-Stokes  equations;  contact  outlet  area Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In the classical Reynolds equation-based modeling of lubrication, the exit area is only considered through a pressure boundary condition which fails to predict the remaining amount of lubricant on each moving surface after the film rupture. A two-phase flow model using the Navier-Stokes equations and a diffuse interface approach is developed to analyze the lubricant behavior at the exit of rolling and sliding lubricated line contacts. After physical and numerical descriptions of the two-phase flow model, results are compared with experimental data from the literature. Good agreements are found concerning pressure profiles and meniscus exit abscissas. The model is then used to study in detail the flow behavior at the exit for different surface tensions. It is shown that when surface tension effects are important, recirculation areas occur downstream the air/oil meniscus. Sliding effects on fluid distribution are then investigated. Finally, an analytical approach is proposed, as a synthesis of the numerical results. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE9000134000004 [...] [article] A two-phase flow approach for the outlet of lubricated line contacts [texte imprimé] / V. Bruyere, Auteur ; N. Fillot, Auteur ; G. E. Morales-Espejel, Auteur . - 2012 . - 10 p. tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 134 N° 04 (Octobre 2012) . - 10 p. Mots-clés : hydrodynamic  lubrication;  two-phase  flow;  Navier-Stokes  equations;  contact  outlet  area Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In the classical Reynolds equation-based modeling of lubrication, the exit area is only considered through a pressure boundary condition which fails to predict the remaining amount of lubricant on each moving surface after the film rupture. A two-phase flow model using the Navier-Stokes equations and a diffuse interface approach is developed to analyze the lubricant behavior at the exit of rolling and sliding lubricated line contacts. After physical and numerical descriptions of the two-phase flow model, results are compared with experimental data from the literature. Good agreements are found concerning pressure profiles and meniscus exit abscissas. The model is then used to study in detail the flow behavior at the exit for different surface tensions. It is shown that when surface tension effects are important, recirculation areas occur downstream the air/oil meniscus. Sliding effects on fluid distribution are then investigated. Finally, an analytical approach is proposed, as a synthesis of the numerical results. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE9000134000004 [...]