Documents disponibles écrits par cet auteur

Computational dynamics of a thermally decomposable viscoelastic lubricant under shear / T. Chinyoka in Transactions of the ASME . Journal of fluids engineering, Vol. 130 N° 12 (Décembre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 12 (Décembre 2008) . - 7 p. Titre : Computational dynamics of a thermally decomposable viscoelastic lubricant under shear Type de document : texte imprimé Auteurs : T. Chinyoka, Auteur Année de publication : 2009 Article en page(s) : 7 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Dynamics  (Mechanics);  temperature;  fluids;  lubricants;  shear  (Mechanics);  algorithms;  equations;  stress;  viscoelasticity;  delays Résumé : The effect of viscoelasticity on the thermodynamic performance of a thermally decomposable lubricant subjected to shear and Arrhenius kinetics is investigated with direct numerical simulations. A numerical algorithm based on the finite difference method is implemented in time and space with the Oldroyd-B constitutive equation as the model for the viscoelastic liquids. We report enhanced efficiency in the case of a polymeric lubricant as compared with the purely viscous lubricant. In particular, it is demonstrated that the use of polymeric liquids helps to delay the onset of thermal runaway as compared with progressively Newtonian liquids. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27349 [...] [article] Computational dynamics of a thermally decomposable viscoelastic lubricant under shear [texte imprimé] / T. Chinyoka, Auteur . - 2009 . - 7 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 12 (Décembre 2008) . - 7 p. Mots-clés : Dynamics  (Mechanics);  temperature;  fluids;  lubricants;  shear  (Mechanics);  algorithms;  equations;  stress;  viscoelasticity;  delays Résumé : The effect of viscoelasticity on the thermodynamic performance of a thermally decomposable lubricant subjected to shear and Arrhenius kinetics is investigated with direct numerical simulations. A numerical algorithm based on the finite difference method is implemented in time and space with the Oldroyd-B constitutive equation as the model for the viscoelastic liquids. We report enhanced efficiency in the case of a polymeric lubricant as compared with the purely viscous lubricant. In particular, it is demonstrated that the use of polymeric liquids helps to delay the onset of thermal runaway as compared with progressively Newtonian liquids. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27349 [...]

Poiseuille flow of reactive phan–thien–tanner liquids in 1D channel flow / T. Chinyoka in Journal of heat transfer, Vol. 132 N° 11 (Novembre 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 11 (Novembre 2010) . - pp. [111701-1/7] Titre : Poiseuille flow of reactive phan–thien–tanner liquids in 1D channel flow Type de document : texte imprimé Auteurs : T. Chinyoka, Auteur Année de publication : 2010 Article en page(s) : pp. [111701-1/7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Channel  flow  Finite  difference  methods  Flow  simulation  Non-Newtonian  flow  Non-Newtonian  fluids  Poiseuille  flow Index. décimale : 536 Chaleur. Thermodynamique Résumé : We investigate, using direct numerical simulations, the effects of viscoelasticity on pressure driven flows of thermally decomposable liquids in channels. A numerical algorithm based on the finite difference method is implemented in time and space with the Phan–Thien–Tanner as the model for the viscoelastic liquids. The strong dependence of fluid temperature on the Frank–Kamenetskii parameter is shown for various fluid types and the phenomenon of thermal runaway is demonstrated. It is shown that viscoelastic fluids have in general delayed susceptibility to thermal runaway as compared with corresponding inelastic fluids. This paper demonstrates the efficiency of using semi-implicit finite difference schemes in solving transient problems of coupled nonlinear systems. It also provides an understanding of nonisothermal flows of viscoelastic fluids. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Poiseuille flow of reactive phan–thien–tanner liquids in 1D channel flow [texte imprimé] / T. Chinyoka, Auteur . - 2010 . - pp. [111701-1/7]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 11 (Novembre 2010) . - pp. [111701-1/7] Mots-clés : Channel  flow  Finite  difference  methods  Flow  simulation  Non-Newtonian  flow  Non-Newtonian  fluids  Poiseuille  flow Index. décimale : 536 Chaleur. Thermodynamique Résumé : We investigate, using direct numerical simulations, the effects of viscoelasticity on pressure driven flows of thermally decomposable liquids in channels. A numerical algorithm based on the finite difference method is implemented in time and space with the Phan–Thien–Tanner as the model for the viscoelastic liquids. The strong dependence of fluid temperature on the Frank–Kamenetskii parameter is shown for various fluid types and the phenomenon of thermal runaway is demonstrated. It is shown that viscoelastic fluids have in general delayed susceptibility to thermal runaway as compared with corresponding inelastic fluids. This paper demonstrates the efficiency of using semi-implicit finite difference schemes in solving transient problems of coupled nonlinear systems. It also provides an understanding of nonisothermal flows of viscoelastic fluids. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]