Euler–Euler modeling of a gas–solid bubbling fluidized bed with kinetic theory of rough particles

Zhao, Yunhua; Lu, Bing; Zhong, Yingjie

doi:10.1016/j.ces.2013.10.001

Cited by 26 publications

(15 citation statements)

References 46 publications

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“…In addition, it may also be concluded that particle inelasticity plays an important role on the fluctuation energy partition between rotational and translational modes. To get more realistic values for λ , one can solve conservation equations for both translational and rotational granular temperatures . However, this may be still unsatisfied for situations of highly inelastic particles, because the previous kinetic theory models are commonly established by assuming the single particle velocity distribution function is a small perturbation from the local equilibrium distribution function .…”

Section: Resultsmentioning

confidence: 99%

“…To get more realistic values for λ , one can solve conservation equations for both translational and rotational granular temperatures . However, this may be still unsatisfied for situations of highly inelastic particles, because the previous kinetic theory models are commonly established by assuming the single particle velocity distribution function is a small perturbation from the local equilibrium distribution function . In other words, these models are theoretically suitable for nearly elastic particles, and fundamental models for highly elastic particles are worth further research.…”

Section: Resultsmentioning

confidence: 99%

“…In realistic systems, particles are always frictional as well as inelastic. So far, great efforts have been made to incorporate the effect of particle friction into the KTGF . To describe the frictional particle collisions, the combination of the Coulomb friction coefficient and both tangential and normal restitution coefficients is suggested .…”

Section: Introductionmentioning

confidence: 99%

“…So far, great efforts have been made to incorporate the effect of particle friction into the KTGF . To describe the frictional particle collisions, the combination of the Coulomb friction coefficient and both tangential and normal restitution coefficients is suggested . Then, the particle spins can be changed through contact friction or tangential inelasticity, so the pseudothermal state of the particles needs to be described by both the translational and rotational granular temperatures, and the latter one is to characterize the intensity of rotational velocity fluctuations.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Boundary conditions for collisional granular flows of frictional and rotational particles at flat walls

Zhao

Zhong

et al. 2014

AIChE Journal

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in Wiley Online Library (wileyonlinelibrary.com) Collisions between frictional particles and flat walls are determined using Coulomb friction and both tangential and normal restitution, and pseudothermal states of particles are described by both the translational and rotational granular temperatures. Then, new models for the stresses and the fluxes of fluctuation energy for the collisional granular flows at the walls are derived. These new models are tested and compared with the literature data and models. The ratio of rotational to translational granular temperatures is shown to be crucial on accurately predicting the shear stress and energy flux and is dependent on the normalized slip velocity as well as the collisional parameters. Using a theoretical but constant value for this ratio, predictions by the new models could still agree better with the literature data than those by the previous models. Finally, boundary conditions are developed to be used within the framework of kinetic theory of granular flow. V C 2014 American Institute of Chemical Engineers AIChE J, 60: 4065-4075, 2014 Figure 4. Stress ratio over normalized slip velocity for different coefficients of normal restitution. (The lines and symbol have the same meaning as in Figure 3. Besides, red dashed line ---: present model with specified k. Inset: red dashed line ---: specified k.) [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] 4070

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Boundary conditions for collisional granular flows of frictional and rotational particles at flat walls

Zhao

Zhong

et al. 2014

AIChE Journal

Self Cite

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“…However, real particles are usually rough and frictional, leading to particle rotation. More sophisticated models have been developed (Lun, 1991;Goldshtein and Shapiro, 1995;Jenkins and Zhang, 2002;Kumaran, 2006;Chialvo and Sundaresan, 2013;Zhao et al, 2013) that consider particle roughness by including tangential restitution, coefficient of friction and rotational degrees of freedom. However, until now there is no consensus on the best general form for the kinetic theory for rough spheres accounting for the coefficient of friction, the coefficient of tangential restitution and particle rotation.…”

Section: Introductionmentioning

confidence: 99%

Modification of kinetic theory of granular flow for frictional spheres, part II: Model validation

Yang

Padding

Kuipers

2016

Chemical Engineering Science

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Numerical study of gas–solid flow characteristics of cylindrical fluidized beds based on coarse‐grained CFD‐DEM method

Tang,

Li,

Huang

et al. 2024

Can J Chem Eng

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The existing researches lack the comprehensive comparison of the performance of two‐fluid model (TFM) and computational fluid dynamics‐discrete element model (CFD‐DEM) using a cylindrical fluidized bed as a research object. In addition, the applicability of rotational periodic boundary conditions in CFD‐DEM simulations of cylindrical fluidized beds is still unclear. Therefore, taking cylindrical fluidized bed as the object and studying the performance of different simulation methods can provide guidance for the selection of simulation methods in subsequent related studies. In the present study, TFM and coarse‐grained CFD‐DEM were used in simulations of the fluidized bed to evaluate the performance of different numerical methods. Furthermore, the applicability of rotating periodic boundary conditions in CFD‐DEM simulations was investigated. The results show that TFM and coarse‐grained CFD‐DEM perform in general agreement in predicting macro variables (e.g., overall pressure drop and bed height). However, radial void fraction distribution and void fraction probability density function (PDF) distribution of CFD‐DEM agreed better with the experimental data. CFD‐DEM simulations with rotational periodic boundary conditions applied showed lower predicted void fraction PDF peaks at packed bed heights and poorly modelling particle mixing in the central of cylindrical fluidized bed due to changes in the boundary conditions as well as the number of particle parcels. Therefore, both TFM and CFD‐DEM can obtain reasonable macro variables, but CFD‐DEM predicted more accurate gas–solid two‐phase distribution. The CFD‐DEM with rotating periodic boundary conditions could not reasonably predict the pressure drop and gas–solid two‐phase distribution inside the cylindrical fluidized bed.

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Euler–Euler modeling of a gas–solid bubbling fluidized bed with kinetic theory of rough particles

Cited by 26 publications

References 46 publications

Boundary conditions for collisional granular flows of frictional and rotational particles at flat walls

Boundary conditions for collisional granular flows of frictional and rotational particles at flat walls

Modification of kinetic theory of granular flow for frictional spheres, part II: Model validation

Numerical study of gas–solid flow characteristics of cylindrical fluidized beds based on coarse‐grained CFD‐DEM method

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