Documents disponibles écrits par cet auteur

Computational and experimental study of heat transfer and hydrodynamics in a 2D gas − solid fluidized bed reactor / Mahdi Hamzehei in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5110–5121 Titre : Computational and experimental study of heat transfer and hydrodynamics in a 2D gas − solid fluidized bed reactor Type de document : texte imprimé Auteurs : Mahdi Hamzehei, Auteur ; Hassan Rahimzadeh, Auteur ; Goodarz Ahmadi, Auteur Année de publication : 2010 Article en page(s) : pp. 5110–5121 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat  Transfer  Hydrodynamics. Résumé : The heat transfer and hydrodynamics of a two-dimensional nonreactive gas−solid fluidized bed reactor were studied experimentally and computationally. A multifluid Eulerian computational model incorporating the kinetic theory for solid particles coupled with the k−ε turbulence model was developed and used to simulate the heat conducting gas−solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal−O’Brien, Gidaspow, and Cao−Ahmadi drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas−solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat-transfer and the hydrodynamic behavior of gas−solid fluidized bed flows with reasonable accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900510a [article] Computational and experimental study of heat transfer and hydrodynamics in a 2D gas − solid fluidized bed reactor [texte imprimé] / Mahdi Hamzehei, Auteur ; Hassan Rahimzadeh, Auteur ; Goodarz Ahmadi, Auteur . - 2010 . - pp. 5110–5121. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5110–5121 Mots-clés : Heat  Transfer  Hydrodynamics. Résumé : The heat transfer and hydrodynamics of a two-dimensional nonreactive gas−solid fluidized bed reactor were studied experimentally and computationally. A multifluid Eulerian computational model incorporating the kinetic theory for solid particles coupled with the k−ε turbulence model was developed and used to simulate the heat conducting gas−solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal−O’Brien, Gidaspow, and Cao−Ahmadi drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas−solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat-transfer and the hydrodynamic behavior of gas−solid fluidized bed flows with reasonable accuracy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900510a

Experimental and numerical study of hydrodynamics with heat transfer in a gas-solid fluidized-bed reactor at different particle sizes / Mahdi Hamzehei in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3177–3186 Titre : Experimental and numerical study of hydrodynamics with heat transfer in a gas-solid fluidized-bed reactor at different particle sizes Type de document : texte imprimé Auteurs : Mahdi Hamzehei, Auteur ; Hassan Rahimzadeh, Auteur Année de publication : 2009 Article en page(s) : pp. 3177–3186 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Nonreactive  gas-solid  fluidized-bed  reactor  Hydrodynamics  Heat  transfer  Eulerian  model  Computational  fluid  dynamics Résumé : In this research, particle size effect on heat transfer and hydrodynamics of a nonreactive gas−solid fluidized-bed reactor were studied experimentally and computationally. A multifluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady-state behavior of this reactor and momentum exchange coefficients were calculated by using the Syamlal−O’Brien drag functions. Simulation results were compared with the experimental data to validate the computational fluid dynamics (CFD) model. Pressure drops and temperature distribution predicted by the simulations at different particle sizes were in good agreement with experimental measurements at superficial gas velocity higher than the minimum fluidization velocity. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upward forming larger bubbles. The influence of solid particles size on the gas temperature was studied. The results indicated that, for smaller particle size, due to a higher heat-transfer coefficient between the gas and solid phases, solid-phase temperature increases and mean gas temperature decrease, rapidly. Furthermore, this comparison showed that the model can predict hydrodynamic and heat-transfer behavior of gas−solid fluidized-bed reactors reasonably well. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801413q [article] Experimental and numerical study of hydrodynamics with heat transfer in a gas-solid fluidized-bed reactor at different particle sizes [texte imprimé] / Mahdi Hamzehei, Auteur ; Hassan Rahimzadeh, Auteur . - 2009 . - pp. 3177–3186. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3177–3186 Mots-clés : Nonreactive  gas-solid  fluidized-bed  reactor  Hydrodynamics  Heat  transfer  Eulerian  model  Computational  fluid  dynamics Résumé : In this research, particle size effect on heat transfer and hydrodynamics of a nonreactive gas−solid fluidized-bed reactor were studied experimentally and computationally. A multifluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady-state behavior of this reactor and momentum exchange coefficients were calculated by using the Syamlal−O’Brien drag functions. Simulation results were compared with the experimental data to validate the computational fluid dynamics (CFD) model. Pressure drops and temperature distribution predicted by the simulations at different particle sizes were in good agreement with experimental measurements at superficial gas velocity higher than the minimum fluidization velocity. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upward forming larger bubbles. The influence of solid particles size on the gas temperature was studied. The results indicated that, for smaller particle size, due to a higher heat-transfer coefficient between the gas and solid phases, solid-phase temperature increases and mean gas temperature decrease, rapidly. Furthermore, this comparison showed that the model can predict hydrodynamic and heat-transfer behavior of gas−solid fluidized-bed reactors reasonably well. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801413q