Abstract
This paper presents a numerical analysis of the combined effect of cohesive van der Waals force and particle shape on bubble dynamics in gas fluidization. The van der Waals force is incorporated into the CFD-DEM model and the magnitude varies from 0 to 20 times Hamaker constant (Ha = 2.1 × 10−21 J), representing non-cohesive to highly cohesive particles. Particles with aspect ratios at 0.5 (oblate), 1 (spherical) and 2 (prolate) are employed to represent disc-like, spherical and rod-like particles, respectively. The results show that under the influence of cohesive force, features such as bubble splitting and coalescence are affected significantly by aspect ratios of ellipsoidal particles. With the increase of Hamaker constant, bubble size and rising velocity decrease, and the bubble shape becomes irregular and vertically oblong. Moreover, the increase of van der Waals force leads to the transformation to non-bubbling fluidization for ellipsoids, but channelling occurs for spheres.
| Original language | English |
|---|---|
| Article number | 115343 |
| Number of pages | 17 |
| Journal | Chemical Engineering Science |
| Volume | 212 |
| DOIs | |
| Publication status | Published - 2 Feb 2020 |
Keywords
- Bubble dynamics
- CFD-DEM
- Non-spherical particles
- van der Waals force
Cite this
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Effect of van der Waals force on bubble dynamics in bubbling fluidized beds of ellipsoidal particles. / Shrestha, S.; Kuang, S.B.; Yu, A.B.; Zhou, Z.Y.
In: Chemical Engineering Science, Vol. 212, 115343, 02.02.2020.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Effect of van der Waals force on bubble dynamics in bubbling fluidized beds of ellipsoidal particles
AU - Shrestha, S.
AU - Kuang, S.B.
AU - Yu, A.B.
AU - Zhou, Z.Y.
PY - 2020/2/2
Y1 - 2020/2/2
N2 - This paper presents a numerical analysis of the combined effect of cohesive van der Waals force and particle shape on bubble dynamics in gas fluidization. The van der Waals force is incorporated into the CFD-DEM model and the magnitude varies from 0 to 20 times Hamaker constant (Ha = 2.1 × 10−21 J), representing non-cohesive to highly cohesive particles. Particles with aspect ratios at 0.5 (oblate), 1 (spherical) and 2 (prolate) are employed to represent disc-like, spherical and rod-like particles, respectively. The results show that under the influence of cohesive force, features such as bubble splitting and coalescence are affected significantly by aspect ratios of ellipsoidal particles. With the increase of Hamaker constant, bubble size and rising velocity decrease, and the bubble shape becomes irregular and vertically oblong. Moreover, the increase of van der Waals force leads to the transformation to non-bubbling fluidization for ellipsoids, but channelling occurs for spheres.
AB - This paper presents a numerical analysis of the combined effect of cohesive van der Waals force and particle shape on bubble dynamics in gas fluidization. The van der Waals force is incorporated into the CFD-DEM model and the magnitude varies from 0 to 20 times Hamaker constant (Ha = 2.1 × 10−21 J), representing non-cohesive to highly cohesive particles. Particles with aspect ratios at 0.5 (oblate), 1 (spherical) and 2 (prolate) are employed to represent disc-like, spherical and rod-like particles, respectively. The results show that under the influence of cohesive force, features such as bubble splitting and coalescence are affected significantly by aspect ratios of ellipsoidal particles. With the increase of Hamaker constant, bubble size and rising velocity decrease, and the bubble shape becomes irregular and vertically oblong. Moreover, the increase of van der Waals force leads to the transformation to non-bubbling fluidization for ellipsoids, but channelling occurs for spheres.
KW - Bubble dynamics
KW - CFD-DEM
KW - Non-spherical particles
KW - van der Waals force
UR - http://www.scopus.com/inward/record.url?scp=85074877205&partnerID=8YFLogxK
U2 - 10.1016/j.ces.2019.115343
DO - 10.1016/j.ces.2019.115343
M3 - Article
VL - 212
JO - Chemical Engineering Science
JF - Chemical Engineering Science
SN - 0009-2509
M1 - 115343
ER -