Drag-induced particle segregation with vibrating boundaries

Wylie, Jonathan J.; Zhang, Qiang; Xu, H. Y.; Sun, Xiucong

doi:10.1209/0295-5075/81/54001

Cited by 21 publications

(17 citation statements)

References 14 publications

(15 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The model coefficients for such systems are attainable via PR-DNS, which are not limited to a narrow parameter space as is their analytical counterpart. Such work is expected to be important for a wide range of practical applications and physical phenomena, such as systems in which the interstitial gas has been shown to have an impact on the stability of the homogeneous state (Koch 1990;Garzó 2005) or on species segregation (Möbius et al 2001;Naylor, Swift & King 2003;Yan et al 2003;Sánchez, Swift & King 2004;Möbius et al 2005;Wylie et al 2008;Zeilstra, van der Hoef & Kuipers 2008;Idler et al 2009;Clement et al 2010). Finally, this work serves as a proof-of-concept for the use of PR-DNS-based models for instantaneous particle acceleration in the starting kinetic equation; this approach can in principle be extended to more complex flows such as those requiring an anisotropic Langevin model.…”

Section: Discussionmentioning

confidence: 99%

Enskog kinetic theory for monodisperse gas–solid flows

et al. 2012

View full text Add to dashboard Cite

The Enskog kinetic theory is used as a starting point to model a suspension of solid particles in a viscous gas. Unlike previous efforts for similar suspensions, the gas-phase contribution to the instantaneous particle acceleration appearing in the Enskog equation is modelled using a Langevin equation, which can be applied to a wide parameter space (e.g. high Reynolds number). Attention here is limited to low Reynolds number flow, however, in order to assess the influence of the gas phase on the constitutive relations, which was assumed to be negligible in a previous analytical treatment. The Chapman–Enskog method is used to derive the constitutive relations needed for the conservation of mass, momentum and granular energy. The results indicate that the Langevin model for instantaneous gas–solid force matches the form of the previous analytical treatment, indicating the promise of this method for regions of the parameter space outside of those attainable by analytical methods (e.g. higher Reynolds number). The results also indicate that the effect of the gas phase on the constitutive relations for the solid-phase shear viscosity and Dufour coefficient is non-negligible, particularly in relatively dilute systems. Moreover, unlike their granular (no gas phase) counterparts, the shear viscosity in gas–solid systems is found to be zero in the dilute limit and the Dufour coefficient is found to be non-zero in the elastic limit.

show abstract

Section: Discussionmentioning

confidence: 99%

Enskog kinetic theory for monodisperse gas–solid flows

et al. 2012

View full text Add to dashboard Cite

show abstract

“…However, the effect of the interstitial fluid on solid particles turns out to be significant in a wide range of practical applications and physical phenomena [6], like for instance species segregation (see for instance, Refs. [7][8][9][10][11][12][13][14][15][16]) or in biophysics where active matter may be considered as a driven granular suspension [17]. For this reason the study of gas-solid flows has attracted the attention of engineering and the physics community in the last few years [18].…”

Section: Introductionmentioning

confidence: 99%

Non-Newtonian hydrodynamics for a dilute granular suspension under uniform shear flow

2015

View full text Add to dashboard Cite

We study in this work a steady shearing laminar flow with null heat flux (usually called "uniform shear flow") in a gas-solid suspension at low density. The solid particles are modeled as a gas of smooth hard spheres with inelastic collisions while the influence of the surrounding interstitial fluid on the dynamics of grains is modeled by means of a volume drag force, in the context of a rheological model for suspensions. The model is solved by means of three different but complementary routes, two of them being theoretical (Grad's moment method applied to the corresponding Boltzmann equation and an exact solution of a kinetic model adapted to granular suspensions) and the other being computational (Monte Carlo simulations of the Boltzmann equation). Unlike in previous studies on granular sheared suspensions, the collisional moment associated with the momentum transfer is determined in Grad's solution by including all the quadratic terms in the stress tensor. This theoretical enhancement allows us for the detection and evaluation of the normal stress differences in the plane normal to the laminar flow. In addition, the exact solution of the kinetic model gives the explicit form of the velocity moments of the velocity distribution function. Comparison between our theoretical and numerical results shows in general a good agreement for the non-Newtonian rheological properties, the kurtosis (fourth velocity moment of the distribution function) and the velocity distribution of the kinetic model for quite strong inelasticity and not too large values of the (scaled) friction coefficient characterizing the viscous drag force. This shows the accuracy of our analytical results that allows us to describe in detail the flow dynamics of the granular sheared suspension.

show abstract

“…The model coefficients for such systems are attainable via PR-DNS, which are not limited to a narrow parameter space as is their analytical counterpart. Such work is expected to be important for a wide range of practical applications and Enskog kinetic theory for monodisperse gas-solid flows 29 physical phenomenon, such as systems in which the interstitial gas has been shown to have an impact on the stability of the homogeneous state Garzó 2005) or on species segregation (Möbius et al 2001;Naylor et al 2003;Sánchez et al 2004;Möbius et al 2005;Wylie et al 2008;Zeilstra et al 2008;Idler et al 2009;Clement et al 2010).…”

Section: Discussionmentioning

confidence: 99%

Development, Verification, and Validation of Multiphase Models for Polydisperse Flows

Hrenya¹,

Cocco²,

Fox³

et al. 2011

View full text Add to dashboard Cite

This report describes in detail the technical findings of the DOE Award entitled "Development, Verification, and Validation of Multiphase Models for Polydisperse Flows." The focus was on high-velocity, gas-solid flows with a range of particle sizes. A complete mathematical model was developed based on first principles and incorporated into MFIX. The solid-phase description took two forms: the Kinetic Theory of Granular Flows (KTGF) and Discrete Quadrature Method of Moments (DQMOM). The gas-solid drag law for polydisperse flows was developed over a range of flow conditions using Discrete Numerical Simulations (DNS). These models were verified via examination of a range of limiting cases and comparison with Discrete Element Method (DEM) data. Validation took the form of comparison with both DEM and experimental data. Experiments were conducted in three separate circulating fluidized beds (CFB's), with emphasis on the riser section. Measurements included bulk quantities like pressure drop and elutriation, as well as axial and radial measurements of bubble characteristics, cluster characteristics, solids flux, and differential pressure drops (axial only). Monodisperse systems were compared to their binary and continuous particle size distribution (PSD) counterparts. The continuous distributions examined included Gaussian, lognormal, and NETLprovided data for a coal gasifier.FINAL TECHNICAL 4 DE-FC26-07NT43098 5 EXECUTIVE SUMMARYThis report is the final technical report for the award DE-FC26-07NT43098 entitled "Development, Verification, and Validation of Multiphase Models for Polydisperse Flows." Below is a summary of work completed under the grant for each of the major goals. Goal I: Continuum Theory for Solid PhaseTwo separate and complementary continuum theories were derived to model polydisperse solids: the kinetic theory of granular flow (KTGF) and the discrete quadrature method of moments (DQMOM). Both theories are based on first principles with no adjustable parameters. The polydisperse KTGF and DQMOM were then encoded in MFIX, and underwent a wide range of verification testing to ensure, to the best possible extent, that no coding errors were present. These verification tests included both granular and gas-solid flows, including cases where an analytical solution and/or DEM (discrete element method) data and/or simple test cases. For the case of KTGF, another set of constitutive equations were derived which rigorously incorporated the gas phase for a simplified case of monodisperse systems at low Reynolds numbers. This derivation used the acceleration model developed in Task 2 from direct numerical simulations (DNS) in the starting kinetic equation, and indicated the effect of the fluid phase on the resulting constitutive relations. Goal II: Improved Gas-Particle Drag Laws -effect of particle size distributionIn this portion of the effort, two types of direct numerical simulations (DNS) were used to extract the drag force experienced by particles in a polydisperse suspension. These two methods, na...

show abstract

Drag-induced particle segregation with vibrating boundaries

Cited by 21 publications

References 14 publications

Enskog kinetic theory for monodisperse gas–solid flows

Enskog kinetic theory for monodisperse gas–solid flows

Non-Newtonian hydrodynamics for a dilute granular suspension under uniform shear flow

Development, Verification, and Validation of Multiphase Models for Polydisperse Flows

Contact Info

Product

Resources

About