Documents disponibles écrits par cet auteur

CFD simulation of the bubbling and slugging gas-solid fluidized beds / Seyyed Hossein Hosseini in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 4 (Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 4 (Avril 2010) . - 10 p. Titre : CFD simulation of the bubbling and slugging gas-solid fluidized beds Type de document : texte imprimé Auteurs : Seyyed Hossein Hosseini, Auteur ; Wenqi Zhong, Auteur ; Mohsen Nasr Esfahany, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : temperature;  particulate  matter;  drag  (fluid  dynamics);  simulation;  fluidization;  computational  fluid  dynamics;  equations;  errors;  fluidized  beds;  pressure  drop Résumé : A two-dimensional transient Eulerian model integrating the kinetic theory for emulsion phase is used to simulate the bubbling and slugging gas-solid fluidized beds, including the Geldart B and D particles, respectively. CFD results show that utilizing an algebraic granular temperature equation, instead of a full granular temperature, one leads to a significant reduction in computational time without loosing accuracy. Different drag models have been examined in the current study. CFD results show that the Syamlal–O’Brien and Di Felice adjusted drag models, based on minimum fluidization velocity, are not suitable for the bed, including coarse particles (Geldart group B). The Gidaspow drag model displays better results in comparison with the others. A good agreement with the available experimental data and the researcher’s findings has been reached quantitatively and qualitatively. The proposed model can reasonably be used for simulation of slugging fluidized beds. This study reduces the computational error compared with the previous works. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] CFD simulation of the bubbling and slugging gas-solid fluidized beds [texte imprimé] / Seyyed Hossein Hosseini, Auteur ; Wenqi Zhong, Auteur ; Mohsen Nasr Esfahany, Auteur . - 2010 . - 10 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 4 (Avril 2010) . - 10 p. Mots-clés : temperature;  particulate  matter;  drag  (fluid  dynamics);  simulation;  fluidization;  computational  fluid  dynamics;  equations;  errors;  fluidized  beds;  pressure  drop Résumé : A two-dimensional transient Eulerian model integrating the kinetic theory for emulsion phase is used to simulate the bubbling and slugging gas-solid fluidized beds, including the Geldart B and D particles, respectively. CFD results show that utilizing an algebraic granular temperature equation, instead of a full granular temperature, one leads to a significant reduction in computational time without loosing accuracy. Different drag models have been examined in the current study. CFD results show that the Syamlal–O’Brien and Di Felice adjusted drag models, based on minimum fluidization velocity, are not suitable for the bed, including coarse particles (Geldart group B). The Gidaspow drag model displays better results in comparison with the others. A good agreement with the available experimental data and the researcher’s findings has been reached quantitatively and qualitatively. The proposed model can reasonably be used for simulation of slugging fluidized beds. This study reduces the computational error compared with the previous works. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Experimental study of the effect of particle density on mixing behavior in a spout-fluid bed / Baosheng Jin in Industrial & engineering chemistry research, Vol. 48 N° 22 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10055–10064 Titre : Experimental study of the effect of particle density on mixing behavior in a spout-fluid bed Type de document : texte imprimé Auteurs : Baosheng Jin, Auteur ; Yong Zhang, Auteur ; Wenqi Zhong, Auteur Année de publication : 2010 Article en page(s) : pp. 10055–10064 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Mixing  behavior  Spout-fluid  bed  Experimental  study Résumé : The particle mixing behavior has been investigated experimentally in a spout-fluid bed. The bed material used is polypropylene particles, and the tracer employed is chosen from silica gel, mung beans, and glass beads. During all experiments, the completely segregated arrangement of particles is adopted as the initial packing condition. The gas velocity varies to cover internal jet, minimum spouting, and fully developed spouting conditions, in order to establish a full mixing map about the effect of particle density. The mixing behavior is analyzed in terms of flow patterns, concentration profile, and mixing index. The results show that the degree and rate of mixing are significantly affected by the particle density, and heavier particles achieve a higher mixing rate but a poorer mixing quality. The mixing map reveals that to reach the same mixing index, the spouting gas velocity needs to increase with the increase of particle density. Besides, provided that the jet gas velocity does not exceed the minimum spouting gas velocity, a segregation phenomenon can always be observed by simply adjusting the ratio of the fluidizing to spouting gas velocity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900689r [article] Experimental study of the effect of particle density on mixing behavior in a spout-fluid bed [texte imprimé] / Baosheng Jin, Auteur ; Yong Zhang, Auteur ; Wenqi Zhong, Auteur . - 2010 . - pp. 10055–10064. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 10055–10064 Mots-clés : Mixing  behavior  Spout-fluid  bed  Experimental  study Résumé : The particle mixing behavior has been investigated experimentally in a spout-fluid bed. The bed material used is polypropylene particles, and the tracer employed is chosen from silica gel, mung beans, and glass beads. During all experiments, the completely segregated arrangement of particles is adopted as the initial packing condition. The gas velocity varies to cover internal jet, minimum spouting, and fully developed spouting conditions, in order to establish a full mixing map about the effect of particle density. The mixing behavior is analyzed in terms of flow patterns, concentration profile, and mixing index. The results show that the degree and rate of mixing are significantly affected by the particle density, and heavier particles achieve a higher mixing rate but a poorer mixing quality. The mixing map reveals that to reach the same mixing index, the spouting gas velocity needs to increase with the increase of particle density. Besides, provided that the jet gas velocity does not exceed the minimum spouting gas velocity, a segregation phenomenon can always be observed by simply adjusting the ratio of the fluidizing to spouting gas velocity. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900689r

Mixing and segregation behavior in a spout-fluid bed / Yong Zhang in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14247–14257 Titre : Mixing and segregation behavior in a spout-fluid bed : Effect of particle size Type de document : texte imprimé Auteurs : Yong Zhang, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur Année de publication : 2013 Article en page(s) : pp. 14247–14257 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fluid  bed Résumé : The mixing and segregation behavior of a binary mixture have been investigated experimentally in a spout-fluid bed. Three types of binary mixtures were used by mixing glass beads with equal density and dissimilar size. The spouting and fluidizing gas flow rate were adjusted to cover a range of flow regimes, typically including internal jet (IJ), jet in fluidized bed with bubbling (JFB), spouting (S) and spout-fluid (SF). The mixing and segregation behavior were analyzed in terms of flow regimes, concentration profile, and mixing index. The results show that in IJ, the particle circulation is combined with the local segregation where smaller particles migrate to the interface between the jet and stagnant region, even into the latter. In S, the distribution of particle depends greatly on the fountain structure. In JFB, the axial segregation takes place where the smaller particles prevail in the upper part of the bed. Segregation becomes more pronounced with increasing the particle size difference. In addition, a mixing/segregation pattern map is constructed. Three regions including mixing region, segregation region, and intermediate region, are identified by the criterion of mixing index. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301005n [article] Mixing and segregation behavior in a spout-fluid bed : Effect of particle size [texte imprimé] / Yong Zhang, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur . - 2013 . - pp. 14247–14257. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14247–14257 Mots-clés : Fluid  bed Résumé : The mixing and segregation behavior of a binary mixture have been investigated experimentally in a spout-fluid bed. Three types of binary mixtures were used by mixing glass beads with equal density and dissimilar size. The spouting and fluidizing gas flow rate were adjusted to cover a range of flow regimes, typically including internal jet (IJ), jet in fluidized bed with bubbling (JFB), spouting (S) and spout-fluid (SF). The mixing and segregation behavior were analyzed in terms of flow regimes, concentration profile, and mixing index. The results show that in IJ, the particle circulation is combined with the local segregation where smaller particles migrate to the interface between the jet and stagnant region, even into the latter. In S, the distribution of particle depends greatly on the fountain structure. In JFB, the axial segregation takes place where the smaller particles prevail in the upper part of the bed. Segregation becomes more pronounced with increasing the particle size difference. In addition, a mixing/segregation pattern map is constructed. Three regions including mixing region, segregation region, and intermediate region, are identified by the criterion of mixing index. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301005n

Study on the drag of a cylinder-shaped particle in steady upward gas flow / Bing Ren in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7593-7600 Titre : Study on the drag of a cylinder-shaped particle in steady upward gas flow Type de document : texte imprimé Auteurs : Bing Ren, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur Année de publication : 2011 Article en page(s) : pp. 7593-7600 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas  flow  Drag Résumé : Studies on the drag of 28 kinds of cylinder-shaped particles with different sizes and materials were experimentally carried out in steady upward gas flow. The drags were determined by high-resolution digital image processing. Two charge-coupled devices with different frame rates were employed to record the particle movements during experimental investigations. The effects of particle properties (length, diameter, density, and sphericity) and operating conditions (gas velocity and particle Reynolds number) on drag coefficients of single falling cylinder have been systematically tested. The results showed that the drag coefficient first declines sharply and then gradually with increasing particle Reynolds number; finally, it can reach a constant level if the Reynolds number is large enough to exceed a certain value. It was found that the drag coefficient is significantly dependent on particle shape and size for a fixed particle Reynolds number. It increases with increasing particle length and density but decreases with increasing particle diameter and sphericity. In addition, the usability of correlations in publications for predicting the drag coefficient was evaluated by comparing our experimental data. A new correlation considering the effect of particle size, shape, orientation, and density was proposed for predicting the drag coefficient for cylinders, which was in satisfactory agreement with the present experiments and some published experimental results. The correlation is helpful for predicting the drag coefficient for cylinders in ranges of the particle Reynolds number Rep = 500―10 500, flatness ratio da/dv = 0.95―1.28, and sphericity ϕ = 0.70―0.87. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239076 [article] Study on the drag of a cylinder-shaped particle in steady upward gas flow [texte imprimé] / Bing Ren, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur . - 2011 . - pp. 7593-7600. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7593-7600 Mots-clés : Gas  flow  Drag Résumé : Studies on the drag of 28 kinds of cylinder-shaped particles with different sizes and materials were experimentally carried out in steady upward gas flow. The drags were determined by high-resolution digital image processing. Two charge-coupled devices with different frame rates were employed to record the particle movements during experimental investigations. The effects of particle properties (length, diameter, density, and sphericity) and operating conditions (gas velocity and particle Reynolds number) on drag coefficients of single falling cylinder have been systematically tested. The results showed that the drag coefficient first declines sharply and then gradually with increasing particle Reynolds number; finally, it can reach a constant level if the Reynolds number is large enough to exceed a certain value. It was found that the drag coefficient is significantly dependent on particle shape and size for a fixed particle Reynolds number. It increases with increasing particle length and density but decreases with increasing particle diameter and sphericity. In addition, the usability of correlations in publications for predicting the drag coefficient was evaluated by comparing our experimental data. A new correlation considering the effect of particle size, shape, orientation, and density was proposed for predicting the drag coefficient for cylinders, which was in satisfactory agreement with the present experiments and some published experimental results. The correlation is helpful for predicting the drag coefficient for cylinders in ranges of the particle Reynolds number Rep = 500―10 500, flatness ratio da/dv = 0.95―1.28, and sphericity ϕ = 0.70―0.87. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239076