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Combined effects of shear thinning and viscous heating on EHL characteristics of rolling/sliding line contacts / Punit Kumar in Transactions of the ASME . Journal of tribology, Vol. 130 N° 4 (Octobre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 13 p. Titre : Combined effects of shear thinning and viscous heating on EHL characteristics of rolling/sliding line contacts Type de document : texte imprimé Auteurs : Punit Kumar, Auteur ; M. M. Khonsari, Auteur Article en page(s) : 13 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Temperature  Fluids  Lubricants  Shear  (Mechanics)  Equations  Film  thickness  Heating  Stress  Pressure  Viscosity Résumé : The combined influence of shear thinning and viscous heating on the behavior of film thickness and friction in elastohydrodynamic lubrication (EHL) rolling/sliding line contacts is investigated numerically. The constitutive equation put forward by Carreau is incorporated into the model to describe shear thinning. An extensive set of numerical simulations is presented. Comparison of the film thickness predictions with published experiments reveals good agreement, and it is shown that thermal effect plays an important role in the precise estimation of EHL film thickness and friction coefficient. Parametric simulations show that thermal effect in shear-thinning fluids is strongly affected by the power-law index used in the Carreau equation. Comparisons of prediction of the Newtonian fluid model are presented to quantify the degree to which it overestimates the film thickness. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468111 [article] Combined effects of shear thinning and viscous heating on EHL characteristics of rolling/sliding line contacts [texte imprimé] / Punit Kumar, Auteur ; M. M. Khonsari, Auteur . - 13 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 13 p. Mots-clés : Temperature  Fluids  Lubricants  Shear  (Mechanics)  Equations  Film  thickness  Heating  Stress  Pressure  Viscosity Résumé : The combined influence of shear thinning and viscous heating on the behavior of film thickness and friction in elastohydrodynamic lubrication (EHL) rolling/sliding line contacts is investigated numerically. The constitutive equation put forward by Carreau is incorporated into the model to describe shear thinning. An extensive set of numerical simulations is presented. Comparison of the film thickness predictions with published experiments reveals good agreement, and it is shown that thermal effect plays an important role in the precise estimation of EHL film thickness and friction coefficient. Parametric simulations show that thermal effect in shear-thinning fluids is strongly affected by the power-law index used in the Carreau equation. Comparisons of prediction of the Newtonian fluid model are presented to quantify the degree to which it overestimates the film thickness. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468111

EHL circular contact film thickness correction factor for shear-thinning fluids / Punit Kumar in Transactions of the ASME . Journal of tribology, Vol. 130 N° 4 (Octobre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 7 p. Titre : EHL circular contact film thickness correction factor for shear-thinning fluids Type de document : texte imprimé Auteurs : Punit Kumar, Auteur ; M. M. Khonsari, Auteur Article en page(s) : 7 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Fluids  Shear  (Mechanics)  Equations  Film  thickness  Lubricants  Engineering  simulation  Pressure Résumé : An extensive set of full elastohydrodynamic lubrication point contact simulations has been used to develop correction factors to account for the effect of shear-thinning lubricant behavior on the central and minimum film thickness in circular contacts under pure rolling condition. The film thickness for a shear-thinning lubricant can be easily obtained by dividing the corresponding Newtonian film thickness by the appropriate correction factor. Comparisons of the film thickness values obtained using the correction factors have been matched with the published experimental results pertaining to shear-thinning lubricants with a variety of realistic flow and piezoviscous properties under a wide range of operating speed. The good agreement between them establishes the validity and versatility of the correction factors developed in this paper. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468112 [article] EHL circular contact film thickness correction factor for shear-thinning fluids [texte imprimé] / Punit Kumar, Auteur ; M. M. Khonsari, Auteur . - 7 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 7 p. Mots-clés : Fluids  Shear  (Mechanics)  Equations  Film  thickness  Lubricants  Engineering  simulation  Pressure Résumé : An extensive set of full elastohydrodynamic lubrication point contact simulations has been used to develop correction factors to account for the effect of shear-thinning lubricant behavior on the central and minimum film thickness in circular contacts under pure rolling condition. The film thickness for a shear-thinning lubricant can be easily obtained by dividing the corresponding Newtonian film thickness by the appropriate correction factor. Comparisons of the film thickness values obtained using the correction factors have been matched with the published experimental results pertaining to shear-thinning lubricants with a variety of realistic flow and piezoviscous properties under a wide range of operating speed. The good agreement between them establishes the validity and versatility of the correction factors developed in this paper. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468112