Documents disponibles écrits par cet auteur

Experimental study of turbulence transport in a dilute surfactant solution flow investigated by PIV / Weiguo Gu in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 5 (Mai 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 5 (Mai 2010) . - 07 p. Titre : Experimental study of turbulence transport in a dilute surfactant solution flow investigated by PIV Type de document : texte imprimé Auteurs : Weiguo Gu, Auteur ; Yasuo Kawaguchi, Auteur ; Dezhong Wang, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : flow  (dynamics);  channels  (hydraulic  engineering);  turbulence;  viscosity;  kinetic  energy;  drag  (fluid  dynamics);  Reynolds  number;  stress;  rheology;  fluctuations  (physics);  shear  (mechanics);  transportation  systems;  drag  reduction;  surfactants;  water Résumé : Drag-reducing flow of dilute surfactant solution in the two-dimensional channel is investigated experimentally by using particle image velocimetry (PIV) system. Five hundred instantaneous velocity frames of u-v in the x-y plane are taken by PIV for every condition. Fluctuation intensity and instantaneous velocity distributions are discussed in order to study the turbulence transport in the drag-reducing flow. As compared with water, the results show that wall-normal velocity fluctuations in the drag-reducing flow are suppressed significantly, and instantaneous velocity distributions display different features. Moreover, the drag-reducing flow exhibits the reduced inclination angle of turbulence transport and appearance of “zero Reynolds shear stress.” High shear dissipation also appears in some solutions. Based on the analysis of the balance of mean and mean turbulent kinetic energies, it is found that the complex rheology, i.e., the elasticity and viscosity of the solution, is considered as the main factor that change the characteristics of turbulence transport. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27418 [...] [article] Experimental study of turbulence transport in a dilute surfactant solution flow investigated by PIV [texte imprimé] / Weiguo Gu, Auteur ; Yasuo Kawaguchi, Auteur ; Dezhong Wang, Auteur . - 2010 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 5 (Mai 2010) . - 07 p. Mots-clés : flow  (dynamics);  channels  (hydraulic  engineering);  turbulence;  viscosity;  kinetic  energy;  drag  (fluid  dynamics);  Reynolds  number;  stress;  rheology;  fluctuations  (physics);  shear  (mechanics);  transportation  systems;  drag  reduction;  surfactants;  water Résumé : Drag-reducing flow of dilute surfactant solution in the two-dimensional channel is investigated experimentally by using particle image velocimetry (PIV) system. Five hundred instantaneous velocity frames of u-v in the x-y plane are taken by PIV for every condition. Fluctuation intensity and instantaneous velocity distributions are discussed in order to study the turbulence transport in the drag-reducing flow. As compared with water, the results show that wall-normal velocity fluctuations in the drag-reducing flow are suppressed significantly, and instantaneous velocity distributions display different features. Moreover, the drag-reducing flow exhibits the reduced inclination angle of turbulence transport and appearance of “zero Reynolds shear stress.” High shear dissipation also appears in some solutions. Based on the analysis of the balance of mean and mean turbulent kinetic energies, it is found that the complex rheology, i.e., the elasticity and viscosity of the solution, is considered as the main factor that change the characteristics of turbulence transport. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27418 [...]

Interaction of reactions and transport / Stuart W. Churchill in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5132–5145 Titre : Interaction of reactions and transport : homogeneous reactions in a round tube. IV. the first-order effects of flow and heat of reaction Type de document : texte imprimé Auteurs : Stuart W. Churchill, Auteur ; Yu, Bo, Auteur ; Yasuo Kawaguchi, Auteur Année de publication : 2008 Article en page(s) : p. 5132–5145 Note générale : Bibliogr. p. 5144-5145 Langues : Anglais (eng) Mots-clés : Round  tube;  Laminar  flow Résumé : The conversion due to first- and second-order, irreversible, equimolar reactions in fully developed isothermal laminar flow in a round tube was computed exactly for perfect, finite, and negligible molecular diffusion of species and energy. The analogous computations for fully developed turbulent flow were based on an essentially exact velocity distribution but an empirical model for the eddy diffusion of species and energy. The effect of a moderate heat of reaction was computed numerically for constant density, constant viscosity, and adiabatic conditions. The identification and implementation of a new dimensionless variable led to the discovery of several near-invariances and, thereby, to very simple but reasonably accurate algebraic representations for the mixed-mean conversion and the mixed-mean temperature for moderately energetic reactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071229r [article] Interaction of reactions and transport : homogeneous reactions in a round tube. IV. the first-order effects of flow and heat of reaction [texte imprimé] / Stuart W. Churchill, Auteur ; Yu, Bo, Auteur ; Yasuo Kawaguchi, Auteur . - 2008 . - p. 5132–5145. Bibliogr. p. 5144-5145 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5132–5145 Mots-clés : Round  tube;  Laminar  flow Résumé : The conversion due to first- and second-order, irreversible, equimolar reactions in fully developed isothermal laminar flow in a round tube was computed exactly for perfect, finite, and negligible molecular diffusion of species and energy. The analogous computations for fully developed turbulent flow were based on an essentially exact velocity distribution but an empirical model for the eddy diffusion of species and energy. The effect of a moderate heat of reaction was computed numerically for constant density, constant viscosity, and adiabatic conditions. The identification and implementation of a new dimensionless variable led to the discovery of several near-invariances and, thereby, to very simple but reasonably accurate algebraic representations for the mixed-mean conversion and the mixed-mean temperature for moderately energetic reactions. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071229r