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Constitutive models for filtered two - fluid models of fluidized gas – particle flows / Yesim Igci in Industrial & engineering chemistry research, Vol. 50 N° 23 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13190–13201 Titre : Constitutive models for filtered two - fluid models of fluidized gas – particle flows Type de document : texte imprimé Auteurs : Yesim Igci, Auteur ; Sankaran Sundaresan, Auteur Année de publication : 2012 Article en page(s) : pp. 13190–13201 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas  Particle  flows Résumé : Our prior study [Igci et al., AIChE J., 2008, 54, 1431–1448] presented a methodology where computational results obtained through highly resolved simulations of a given microscopic two-fluid model (TFM) for gas-particle flows are filtered to deduce models for the residual correlations appearing in the corresponding filtered TFM equations that are appropriate for coarse-grid simulations of gas-particle flows. In the present study, we have performed a large number of highly resolved simulations of a kinetic theory based TFM in two- and three-dimensional periodic domains using this methodology and filtered the results to generate computational data on the filtered drag coefficient, the filtered particle phase pressure, and the filtered particle phase viscosity. These results have been captured in the form of correlations that can readily be employed in coarse-grid simulations of gas-particle flows. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200190q [article] Constitutive models for filtered two - fluid models of fluidized gas – particle flows [texte imprimé] / Yesim Igci, Auteur ; Sankaran Sundaresan, Auteur . - 2012 . - pp. 13190–13201. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13190–13201 Mots-clés : Gas  Particle  flows Résumé : Our prior study [Igci et al., AIChE J., 2008, 54, 1431–1448] presented a methodology where computational results obtained through highly resolved simulations of a given microscopic two-fluid model (TFM) for gas-particle flows are filtered to deduce models for the residual correlations appearing in the corresponding filtered TFM equations that are appropriate for coarse-grid simulations of gas-particle flows. In the present study, we have performed a large number of highly resolved simulations of a kinetic theory based TFM in two- and three-dimensional periodic domains using this methodology and filtered the results to generate computational data on the filtered drag coefficient, the filtered particle phase pressure, and the filtered particle phase viscosity. These results have been captured in the form of correlations that can readily be employed in coarse-grid simulations of gas-particle flows. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200190q

Drag law for bidisperse gas-solid suspensions containing equally sized spheres / Xiaolong Yin in Industrial & engineering chemistry research, Vol. 48 N°1 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°1 (Janvier 2009) . - P. 227-241 Titre : Drag law for bidisperse gas-solid suspensions containing equally sized spheres Type de document : texte imprimé Auteurs : Xiaolong Yin, Editeur scientifique ; Sankaran Sundaresan, Editeur scientifique Année de publication : 2009 Article en page(s) : P. 227-241 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Gas−Solid  Hard-sphere  fluid  Fluid−particle  relative  velocities Résumé : In this study, we constructed from lattice-Boltzmann simulations a drag correlation for bidisperse gas−solid suspensions containing equally sized particles that are moving with different velocities relative to the interstitial fluid. Our analysis is limited to flows at low Reynolds numbers and high Stokes numbers, and the microstructure of the suspension is identical to that of a hard-sphere fluid. The Stokes drag forces acting on the two particle species are related to the fluid−particle relative velocities by a friction coefficient matrix, the off-diagonal components of which represent the particle−particle drag due to hydrodynamic interactions and were found to give important contributions to the net drag force. The off-diagonals exhibit a logarithmic dependence on the lubrication cutoff distance, a length scale on which the lubrication force between approaching particles begins to level off. In our simulations, the total particle volume fraction ϕ ranges from 0.1 to 0.4, and the volume fraction ratio ϕ1/ϕ2 ranges from 1:1 to 1:7. The results from these simulations are captured in explicit constitutive models, which can be readily generalized to multicomponent mixtures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800171p [article] Drag law for bidisperse gas-solid suspensions containing equally sized spheres [texte imprimé] / Xiaolong Yin, Editeur scientifique ; Sankaran Sundaresan, Editeur scientifique . - 2009 . - P. 227-241. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°1 (Janvier 2009) . - P. 227-241 Mots-clés : Gas−Solid  Hard-sphere  fluid  Fluid−particle  relative  velocities Résumé : In this study, we constructed from lattice-Boltzmann simulations a drag correlation for bidisperse gas−solid suspensions containing equally sized particles that are moving with different velocities relative to the interstitial fluid. Our analysis is limited to flows at low Reynolds numbers and high Stokes numbers, and the microstructure of the suspension is identical to that of a hard-sphere fluid. The Stokes drag forces acting on the two particle species are related to the fluid−particle relative velocities by a friction coefficient matrix, the off-diagonal components of which represent the particle−particle drag due to hydrodynamic interactions and were found to give important contributions to the net drag force. The off-diagonals exhibit a logarithmic dependence on the lubrication cutoff distance, a length scale on which the lubrication force between approaching particles begins to level off. In our simulations, the total particle volume fraction ϕ ranges from 0.1 to 0.4, and the volume fraction ratio ϕ1/ϕ2 ranges from 1:1 to 1:7. The results from these simulations are captured in explicit constitutive models, which can be readily generalized to multicomponent mixtures. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800171p

Lattice Boltzmann Simulation of Two-Fluid Model Equations / Krishnan Sankaranarayanan in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9165–9173 Titre : Lattice Boltzmann Simulation of Two-Fluid Model Equations Type de document : texte imprimé Auteurs : Krishnan Sankaranarayanan, Auteur ; Sankaran Sundaresan, Auteur Année de publication : 2009 Article en page(s) : p. 9165–9173 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Lattice  Boltzmann  Simulation  of  Two-Fluid  Model  Equations Résumé : An implicit lattice Boltzmann equation to simulate the locally averaged flow behavior of disperse two-phase mixtures is presented. Using a multiscale expansion technique, it is shown that these equations reduce to the widely used two-fluid model for flows of such suspensions. The viability of the lattice Boltzmann approach is demonstrated through illustrative examples. The lattice Boltzmann scheme is easy to program and it parallelizes readily. It is suggested that this approach may serve as an attractive alternative to conventional approaches to solving the two-fluid model equations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800283b [article] Lattice Boltzmann Simulation of Two-Fluid Model Equations [texte imprimé] / Krishnan Sankaranarayanan, Auteur ; Sankaran Sundaresan, Auteur . - 2009 . - p. 9165–9173. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9165–9173 Mots-clés : Lattice  Boltzmann  Simulation  of  Two-Fluid  Model  Equations Résumé : An implicit lattice Boltzmann equation to simulate the locally averaged flow behavior of disperse two-phase mixtures is presented. Using a multiscale expansion technique, it is shown that these equations reduce to the widely used two-fluid model for flows of such suspensions. The viability of the lattice Boltzmann approach is demonstrated through illustrative examples. The lattice Boltzmann scheme is easy to program and it parallelizes readily. It is suggested that this approach may serve as an attractive alternative to conventional approaches to solving the two-fluid model equations. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800283b

Unsteady shear of dense assemblies of cohesive granular materials under constant volume conditions / Lee R. Aarons 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. 5153–5165 Titre : Unsteady shear of dense assemblies of cohesive granular materials under constant volume conditions Type de document : texte imprimé Auteurs : Lee R. Aarons, Auteur ; Jin Sun, Auteur ; Sankaran Sundaresan, Auteur Année de publication : 2010 Article en page(s) : pp. 5153–5165 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Granular  materials Résumé : The response characteristics of dense assemblies of cohesive granular materials to unsteady simple shear in the quasi-static regime are investigated through discrete element method (DEM) simulations of monodisperse spherical and frictional particles in periodic domains at constant volume. The dynamics of the volume-averaged normal and shear stresses in materials, undergoing stop-and-go shearing and oscillatory shear, are studied in detail. Furthermore, the evolution of microstructure anisotropy has been quantified through a fabric tensor. The stresses and the microstructure anisotropy depend on the strain extent but not on the shear rate. They both undergo a transition following reversal of shear direction, which requires a shear strain of order unity to fully adapt. The results reveal a correlation between the stress evolution and the microstructure anisotropy development. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901187w [article] Unsteady shear of dense assemblies of cohesive granular materials under constant volume conditions [texte imprimé] / Lee R. Aarons, Auteur ; Jin Sun, Auteur ; Sankaran Sundaresan, Auteur . - 2010 . - pp. 5153–5165. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5153–5165 Mots-clés : Granular  materials Résumé : The response characteristics of dense assemblies of cohesive granular materials to unsteady simple shear in the quasi-static regime are investigated through discrete element method (DEM) simulations of monodisperse spherical and frictional particles in periodic domains at constant volume. The dynamics of the volume-averaged normal and shear stresses in materials, undergoing stop-and-go shearing and oscillatory shear, are studied in detail. Furthermore, the evolution of microstructure anisotropy has been quantified through a fabric tensor. The stresses and the microstructure anisotropy depend on the strain extent but not on the shear rate. They both undergo a transition following reversal of shear direction, which requires a shear strain of order unity to fully adapt. The results reveal a correlation between the stress evolution and the microstructure anisotropy development. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901187w