Documents disponibles écrits par cet auteur

Commentary / Stuart W. Churchill in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8806–8816 Titre : Commentary : the state of the art of education in reaction engineering Type de document : texte imprimé Auteurs : Stuart W. Churchill, Auteur Année de publication : 2011 Article en page(s) : pp. 8806–8816 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reaction  engineering Résumé : An informal survey of recent archival publications indicates that academic and industrial research in reaction engineering are interconnected, and they keep pace with those in the other engineering sciences, with one exception: the textbooks on reaction engineering incorporate many obsolete concepts, neglect some of the advances, and focus on the solution of overly simplified models. It is presumed that these characteristics carry over to the classroom. This is a serious matter, because chemical engineers, throughout their careers, are apt to cling to the concepts and textbooks that they acquire while in school. The simplest and perhaps most effective corrective for these shortcomings is the distribution of electronic supplements by the teacher. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200907s [article] Commentary : the state of the art of education in reaction engineering [texte imprimé] / Stuart W. Churchill, Auteur . - 2011 . - pp. 8806–8816. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8806–8816 Mots-clés : Reaction  engineering Résumé : An informal survey of recent archival publications indicates that academic and industrial research in reaction engineering are interconnected, and they keep pace with those in the other engineering sciences, with one exception: the textbooks on reaction engineering incorporate many obsolete concepts, neglect some of the advances, and focus on the solution of overly simplified models. It is presumed that these characteristics carry over to the classroom. This is a serious matter, because chemical engineers, throughout their careers, are apt to cling to the concepts and textbooks that they acquire while in school. The simplest and perhaps most effective corrective for these shortcomings is the distribution of electronic supplements by the teacher. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200907s

Guidelines for modeling based on experiences with radiantly stabilized combustion / Stuart W. Churchill in Industrial & engineering chemistry research, Vol. 47 N°10 (Mai 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°10 (Mai 2008) . - p. 3410–3429 Titre : Guidelines for modeling based on experiences with radiantly stabilized combustion Type de document : texte imprimé Auteurs : Stuart W. Churchill, Auteur Année de publication : 2008 Article en page(s) : p. 3410–3429 Note générale : Bibliogr. p. 3428-3429 Langues : Anglais (eng) Mots-clés : Combustion;  Radiantly  stabilization Résumé : Many processes of interest in chemical engineering are yet beyond the reach of a numerical solution in a practical sense. For such processes, creative modeling by means of idealizations and approximations and innovative methods of solution may be needed. Homogeneous combustion, because of extreme temperature gradients, developing flow, turbulent convection of momentum, energy, and species, thermal radiation, and a seemingly unlimited array of free-radical reactions, each with a complex and uncertain dependence on temperature, exemplifies such a process. Guidelines for such modeling have been identified from the accumulative experiences of a long sequence of research on one form of combustion, namely that stabilized primarily by thermal radiation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070945q [article] Guidelines for modeling based on experiences with radiantly stabilized combustion [texte imprimé] / Stuart W. Churchill, Auteur . - 2008 . - p. 3410–3429. Bibliogr. p. 3428-3429 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°10 (Mai 2008) . - p. 3410–3429 Mots-clés : Combustion;  Radiantly  stabilization Résumé : Many processes of interest in chemical engineering are yet beyond the reach of a numerical solution in a practical sense. For such processes, creative modeling by means of idealizations and approximations and innovative methods of solution may be needed. Homogeneous combustion, because of extreme temperature gradients, developing flow, turbulent convection of momentum, energy, and species, thermal radiation, and a seemingly unlimited array of free-radical reactions, each with a complex and uncertain dependence on temperature, exemplifies such a process. Guidelines for such modeling have been identified from the accumulative experiences of a long sequence of research on one form of combustion, namely that stabilized primarily by thermal radiation. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070945q

Helical and Lemniscate Tubular Reactors / Charles G. Slominski in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8842–8850 Titre : Helical and Lemniscate Tubular Reactors Type de document : texte imprimé Auteurs : Charles G. Slominski, Auteur ; Warren D. Seider, Auteur ; Stuart W. Churchill, Auteur Année de publication : 2011 Article en page(s) : pp. 8842–8850 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Tubular  reactor Résumé : Introducing curvature in a tubular reactor generates a secondary fluid motion that decreases the variance of the residence-time-distribution of the fluid elements. The conversion is thereby increased with respect to that of a straight tube, and in the extreme approaches the maximum corresponding to perfect radial mixing, which is the same as that for the hypothetical case of plug flow. Helically coiled tubes are widely used as reactors in industry, but experimental data and theoretical solutions are limited in number and scope. The fluid motion and conversion as determined by finite-element solutions using COMSOL is delineated more clearly than in prior studies for helical tubes and is also applied for a lemniscate tube (a figure-eight shape). Coiled tubes, lemniscate tubes, and other such configurations are designed to decrease the variance of the residence-time distribution of the fluid elements at the expense of a minimal increase in the pressure drop. The decrease in the variance of the residence-time distribution results in a reduction in the reactor length for a specified chemical conversion and thus in the floor space required to achieve a particular conversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395830 [article] Helical and Lemniscate Tubular Reactors [texte imprimé] / Charles G. Slominski, Auteur ; Warren D. Seider, Auteur ; Stuart W. Churchill, Auteur . - 2011 . - pp. 8842–8850. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 8842–8850 Mots-clés : Tubular  reactor Résumé : Introducing curvature in a tubular reactor generates a secondary fluid motion that decreases the variance of the residence-time-distribution of the fluid elements. The conversion is thereby increased with respect to that of a straight tube, and in the extreme approaches the maximum corresponding to perfect radial mixing, which is the same as that for the hypothetical case of plug flow. Helically coiled tubes are widely used as reactors in industry, but experimental data and theoretical solutions are limited in number and scope. The fluid motion and conversion as determined by finite-element solutions using COMSOL is delineated more clearly than in prior studies for helical tubes and is also applied for a lemniscate tube (a figure-eight shape). Coiled tubes, lemniscate tubes, and other such configurations are designed to decrease the variance of the residence-time distribution of the fluid elements at the expense of a minimal increase in the pressure drop. The decrease in the variance of the residence-time distribution results in a reduction in the reactor length for a specified chemical conversion and thus in the floor space required to achieve a particular conversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395830

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