A critical comparison of frictional stress models applied to the simulation of bubbling fluidized beds

Passalacqua, Alberto; Marmo, Luca

doi:10.1016/j.ces.2009.03.005

Cited by 84 publications

(43 citation statements)

References 22 publications

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“…A commonly used [18][19][20] Table 3). In Model B, µ s,fr and P s,fr are increased compared to Model A.…”

Section: Frictional Model Studymentioning

confidence: 99%

“…TFM has been shown to be a viable approach to modeling dense particle, gas-particle systems, as long as the appropriate models are implemented correctly [9,[18][19][20][21][22][23][24][25][26][27][28][29]. Thus, TFM is expected to be a viable approach to predicting the interaction of a gas plume with a dense particle bed.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies illustrated the importance of correctly implementing the frictional stress to achieve accurate predictions, and indicate caution should be used when applying frictional models due to their inherent empiricism [9,[18][19][20]. TFM has been shown to be a viable approach to modeling dense particle, gas-particle systems, as long as the appropriate models are implemented correctly [9,[18][19][20][21][22][23][24][25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Two-fluid modeling of cratering in a particle bed by a subsonic turbulent jet

LaMarche

Benavides-Morán

Wachem³

et al. 2017

Powder Technology

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The Two-Fluid Method is capable of modeling large-scale (i.e., lab scale or larger) multiphase (particle-fluid) flows by treating both the fluid and particle phase as interpenetrating continua and solving mass and momentum balances for each phase. To solve for the flow of the solids phase the momentum balance requires constitutive relations in the form of normal and shear stresses ± i.e., pressures and viscosities. However, the stresses that account for frictional contacts in dense particle systems, and are relevant to this work, are empirically based. A study of the effects of adjusting the frictional model formulation (the empirical parameters of the model), by changing the overall frictional stress magnitude and the relative magnitude of the frictional viscosity to the frictional pressure, on the behavior of the bed is presented here. It was found that the magnitude of the frictional viscosity relative to the frictional pressure affects the crater growth prediction almost as much as the magnitude of the overall frictional stress. Additionally, a frictional model formulation is validated for sand particles, and predictions are compared with existing experimental data for the crater formation of a sand bed under a vertical, impinging jet of gas (Metzger et al. J Areo Eng (2008) v22, p24-32). In the low jet velocity regime (subsonic, turbulent jet), the model predicts the salient features previously measured for the growth rate of the crater of time, the profile of the crater, and the response of the crater to turning the jet off. In the high jet velocity regime (compressible, near sonic jet flow) the prediction agrees qualitatively with prior experimental observations.

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“…A commonly used [18][19][20] Table 3). In Model B, µ s,fr and P s,fr are increased compared to Model A.…”

Section: Frictional Model Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two-fluid modeling of cratering in a particle bed by a subsonic turbulent jet

LaMarche

Benavides-Morán

Wachem³

et al. 2017

Powder Technology

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“…Wang et al (2008) used a two fluid model in a 2 D domain to study the flow behavior of particles in a riser; the computed results were compared with experimental particle distributions, velocities and bed expansion ratio measurements reported in literature for 2 D systems. Passalacqua and Marmo (2009) performed a two fluid model simulation of a 2 D bubbling fluidized bed with and without a central jet using different frictional stress models. They compared the equivalent diameter obtained from the area of their simulated bubbles, with experimental data present in the literature.…”

Section: Introductionmentioning

confidence: 99%

Experimental and computational study on the bubble behavior in a 3-D fluidized bed

Acosta-Iborra

Sobrino

Hernández-Jiménez

et al. 2011

Chemical Engineering Science

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a b s t r a c tThe results from a two fluid Eulerian Eulerian three dimensional (3 D) simulation of a cylindrical bed, filled with Geldart B particles and fluidized with air in the bubbling regime, are compared with experimental data obtained from pressure and optical probe measurements in a real bed of similar dimensions and operative conditions. The main objectives of this comparison are to test the validity of the simulation results and to characterize the bubble behavior and bed dynamics. The fluidized bed is 0.193 m internal diameter and 0.8 m height, and it is filled with silica sand particles, reaching a settle height of 0.22 m. A frequency domain analysis of absolute and differential pressure signals in both the measured and the simulated cases shows that the same principal phenomena are reproduced with similar distributions of peak frequencies in the power spectral density (PSD) and width of the spectrum. The local dynamic behavior is also studied in the present work by means of the PSD of the simulated particle fraction and the PSD of the measured optical signal, which reveals as well good agreement between both the spectra. This work also presents, for the first time, comparative results of the measured and the simulated bubble size and velocity in a fully 3 D bed configuration. The values of bubble pierced length and velocity retrieved from the experimental optical signals and from the simulated particle fraction compare fairly well in different radial and axial positions. Very similar values are obtained when these bubble parameters are deduced from either simulated pressure signals or simulated particle volume fraction. In addition, applying the maximum entropy method technique, bubble size probability density functions are also calculated. All these results indicate that the two fluid model is able to reproduce the essential dynamics and interaction between bubbles and dense phase in the 3 D bed studied.

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“…Thus, the rheologic properties of particles, the solid phase pressure, viscosity of particles, conductive energy flux, and dissipation are considered as a function of granular temperature. Simulations using kinetic theory of granular flow have been reported by many researchers in gas-particle fluidization [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In KFGT, the particle flow is assumed to be laminar flows instead of large-scale turbulent flows.…”

Section: Introductionmentioning

confidence: 99%

Particle Dispersion Behaviors of Dense Gas-Particle Flows in Bubble Fluidized Bed

2013

Advances in Mechanical Engineering

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An Euler-Euler two-fluid model incorporating a developed momentum transfer empirical coefficient is developed to study the particle dispersion behaviors of dense gas-particle flows in gas-fluidization reactor. In this model, the four-way couplings among gas-particles, particle-gas, and particle-particle collisions are fully considered based on kinetic theory of granular flows and an improved smooth continuous drag coefficient is utilized. Gas turbulent flow is solved by large eddy simulation. The particle fraction, the time-averaged axial particle velocity, the histogram of particle fluctuation velocity, and the wavelet analysis of pressure signals are obtained. The results are in good agreement with experimental measurements. The mean value and the variance of axial particle velocity are greater than those of radial particle velocities. Particle collision frequencies at bubble vibrant movement regions along axial direction are much higher than those of radial direction and attenuated along height increase. Low-frequency component of pressure signal indicating the bubble movement behaviors in the center of reactor is stronger than wall regions. Furthermore, the negative values represent the passed bubble and positive peak values disclose the continuous motion of single bubble.

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A critical comparison of frictional stress models applied to the simulation of bubbling fluidized beds

Cited by 84 publications

References 22 publications

Two-fluid modeling of cratering in a particle bed by a subsonic turbulent jet

Two-fluid modeling of cratering in a particle bed by a subsonic turbulent jet

Experimental and computational study on the bubble behavior in a 3-D fluidized bed

Particle Dispersion Behaviors of Dense Gas-Particle Flows in Bubble Fluidized Bed

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