Documents disponibles écrits par cet auteur

Enforcing mass conservation in DPM - CFD models of dense particulate flows / C.L. Wu in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.475–481 Titre : Enforcing mass conservation in DPM - CFD models of dense particulate flows Type de document : texte imprimé Auteurs : C.L. Wu, Auteur ; K. Nandakumar, Auteur ; A. S. Berrouk, Auteur Année de publication : 2012 Article en page(s) : pp.475–481 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : Mass  conversation  Discrete  particle/element  modeling  Computational  fluid  dynamics  Dense  particulate  flow Résumé : An improved coupling method is proposed to ensure mass conservation in a previously developed DPM-CFD model (C.L. Wu et al., Three-dimensional discrete particle model for gas–solid fluidized bed on unstructured mesh, Chemical Engineering Journal 152 (2009), 514–529). In enforcing the mass balance for the continuous phase in such algorithms using the single phase flow solvers, any heterogeneity in the particle concentration field (caused by clustering of particles) creates non-zero source terms. It is shown that if this is not handled properly, it can create large numerical errors (of up to 10%) and any oscillation in the flow field manifests itself in a similar error in the mass conservation. By using the conservative form of the equations in integral formulation, the coupling between the DPM and CFD models ensures mass conservation on the global scale in the entire domain, even in the presence of local heterogeneities in the flow field. The method also offers a consistent implementation of mass flow boundaries at the inlet. Numerical results show the superiority of the new coupling method over the previous one in conserving mass and handling transport processes in fluidized beds. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S138589471100979X [article] Enforcing mass conservation in DPM - CFD models of dense particulate flows [texte imprimé] / C.L. Wu, Auteur ; K. Nandakumar, Auteur ; A. S. Berrouk, Auteur . - 2012 . - pp.475–481. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.475–481 Mots-clés : Mass  conversation  Discrete  particle/element  modeling  Computational  fluid  dynamics  Dense  particulate  flow Résumé : An improved coupling method is proposed to ensure mass conservation in a previously developed DPM-CFD model (C.L. Wu et al., Three-dimensional discrete particle model for gas–solid fluidized bed on unstructured mesh, Chemical Engineering Journal 152 (2009), 514–529). In enforcing the mass balance for the continuous phase in such algorithms using the single phase flow solvers, any heterogeneity in the particle concentration field (caused by clustering of particles) creates non-zero source terms. It is shown that if this is not handled properly, it can create large numerical errors (of up to 10%) and any oscillation in the flow field manifests itself in a similar error in the mass conservation. By using the conservative form of the equations in integral formulation, the coupling between the DPM and CFD models ensures mass conservation on the global scale in the entire domain, even in the presence of local heterogeneities in the flow field. The method also offers a consistent implementation of mass flow boundaries at the inlet. Numerical results show the superiority of the new coupling method over the previous one in conserving mass and handling transport processes in fluidized beds. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S138589471100979X

Hydrodynamic simulation of horizontal slurry pipeline flow using ANSYS-CFX / Kalekudithi Ekambara in Industrial & engineering chemistry research, Vol. 48 N° 17 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 17 (Septembre 2009) . - pp. 8159–8171 Titre : Hydrodynamic simulation of horizontal slurry pipeline flow using ANSYS-CFX Type de document : texte imprimé Auteurs : Kalekudithi Ekambara, Auteur ; R. Sean Sanders, Auteur ; K. Nandakumar, Auteur Année de publication : 2009 Article en page(s) : pp. 8159–8171 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Solid−liquid  (slurry)  pipeline  flows  Three-dimensional  hydrodynamic  model  ANSYS-CFX Résumé : The behavior of horizontal solid−liquid (slurry) pipeline flows was predicted using a transient three-dimensional (3D) hydrodynamic model based on the kinetic theory of granular flows. Computational fluid dynamics (CFD) simulation results, obtained using a commercial CFD software package, ANSYS-CFX, were compared with a number of experimental data sets available in the literature. The simulations were carried out to investigate the effect of in situ solids volume concentration (8 to 45%), particle size (90 to 500 μm), mixture velocity (1.5 to 5.5 m/s), and pipe diameter (50 to 500 mm) on local, time-averaged solids concentration profiles, particle and liquid velocity profiles, and frictional pressure loss. Excellent agreement between the model predictions and the experimental data was obtained. The experimental and simulated results indicate that the particles are asymmetrically distributed in the vertical plane with the degree of asymmetry increasing with increasing particle size. Once the particles are sufficiently large, concentration profiles are dependent only on the in situ solids volume fraction. The present CFD model requires no experimentally determined slurry pipeline flow data for parameter tuning, and thus can be considered to be superior to commonly used, correlation-based empirical models. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801505z [article] Hydrodynamic simulation of horizontal slurry pipeline flow using ANSYS-CFX [texte imprimé] / Kalekudithi Ekambara, Auteur ; R. Sean Sanders, Auteur ; K. Nandakumar, Auteur . - 2009 . - pp. 8159–8171. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 17 (Septembre 2009) . - pp. 8159–8171 Mots-clés : Solid−liquid  (slurry)  pipeline  flows  Three-dimensional  hydrodynamic  model  ANSYS-CFX Résumé : The behavior of horizontal solid−liquid (slurry) pipeline flows was predicted using a transient three-dimensional (3D) hydrodynamic model based on the kinetic theory of granular flows. Computational fluid dynamics (CFD) simulation results, obtained using a commercial CFD software package, ANSYS-CFX, were compared with a number of experimental data sets available in the literature. The simulations were carried out to investigate the effect of in situ solids volume concentration (8 to 45%), particle size (90 to 500 μm), mixture velocity (1.5 to 5.5 m/s), and pipe diameter (50 to 500 mm) on local, time-averaged solids concentration profiles, particle and liquid velocity profiles, and frictional pressure loss. Excellent agreement between the model predictions and the experimental data was obtained. The experimental and simulated results indicate that the particles are asymmetrically distributed in the vertical plane with the degree of asymmetry increasing with increasing particle size. Once the particles are sufficiently large, concentration profiles are dependent only on the in situ solids volume fraction. The present CFD model requires no experimentally determined slurry pipeline flow data for parameter tuning, and thus can be considered to be superior to commonly used, correlation-based empirical models. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801505z