On the limitations of 2D CFD for thin-rectangular fluidized bed simulations.
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| Title: | On the limitations of 2D CFD for thin-rectangular fluidized bed simulations. |
|---|---|
| Authors: | Bakshi, A.1,2 abakshi@mit.edu, Altantzis, C.1,2, Bershanska, A.1, Stark, A.K.1,3, Ghoniem, A.F.1 |
| Source: | Powder Technology. Jun2018, Vol. 332, p114-119. 6p. |
| Subjects: | Computational fluid dynamics, Fluidized bed reactors, Hydrodynamics, Energy dissipation, Boundary value problems |
| Abstract: | Thin rectangular fluidized beds enable detailed optical diagnostics providing high quality data for validating numerical simulations. Because of their lower computational costs, 2D CFD continues to be employed despite the high wall surface-area to bed-volume ratio characterizing this geometric setup. 2D simulations do not resolve the gas and solids flow in the third (spanwise) direction nor the true boundary condition along the front and back walls, both of which are critical because the hydrodynamics are significantly affected by the presence these walls whose surface area is often much larger than the walls modeled in 2D analyses. Through highly-resolved simulations of three independent experimental setups, we show that 2D CFD may not capture, even qualitatively, the fluidization hydrodynamics because (a) bubble rise and coalescence mechanisms along the spanwise direction are not resolved, and (b) solids momentum and energy dissipation are under-predicted, and bubble rise velocities are over-predicted, because effects of the front and back walls are not modeled. 3D simulations with suitable wall boundary conditions predict bubbling dynamics and solids mixing in excellent agreement with experimental observations without further tuning of model parameters. Overall, we recommended that 3D numerical simulations be employed to model thin lab-scale setups for model development and validation purposes. [ABSTRACT FROM AUTHOR] |
| Copyright of Powder Technology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 129373426 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: On the limitations of 2D CFD for thin-rectangular fluidized bed simulations. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Bakshi%2C+A%2E%22">Bakshi, A.</searchLink><relatesTo>1,2</relatesTo><i> abakshi@mit.edu</i><br /><searchLink fieldCode="AR" term="%22Altantzis%2C+C%2E%22">Altantzis, C.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Bershanska%2C+A%2E%22">Bershanska, A.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Stark%2C+A%2EK%2E%22">Stark, A.K.</searchLink><relatesTo>1,3</relatesTo><br /><searchLink fieldCode="AR" term="%22Ghoniem%2C+A%2EF%2E%22">Ghoniem, A.F.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Powder+Technology%22">Powder Technology</searchLink>. Jun2018, Vol. 332, p114-119. 6p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Computational+fluid+dynamics%22">Computational fluid dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Fluidized+bed+reactors%22">Fluidized bed reactors</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrodynamics%22">Hydrodynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Energy+dissipation%22">Energy dissipation</searchLink><br /><searchLink fieldCode="DE" term="%22Boundary+value+problems%22">Boundary value problems</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Thin rectangular fluidized beds enable detailed optical diagnostics providing high quality data for validating numerical simulations. Because of their lower computational costs, 2D CFD continues to be employed despite the high wall surface-area to bed-volume ratio characterizing this geometric setup. 2D simulations do not resolve the gas and solids flow in the third (spanwise) direction nor the true boundary condition along the front and back walls, both of which are critical because the hydrodynamics are significantly affected by the presence these walls whose surface area is often much larger than the walls modeled in 2D analyses. Through highly-resolved simulations of three independent experimental setups, we show that 2D CFD may not capture, even qualitatively, the fluidization hydrodynamics because (a) bubble rise and coalescence mechanisms along the spanwise direction are not resolved, and (b) solids momentum and energy dissipation are under-predicted, and bubble rise velocities are over-predicted, because effects of the front and back walls are not modeled. 3D simulations with suitable wall boundary conditions predict bubbling dynamics and solids mixing in excellent agreement with experimental observations without further tuning of model parameters. Overall, we recommended that 3D numerical simulations be employed to model thin lab-scale setups for model development and validation purposes. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Powder Technology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.powtec.2018.03.048 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 6 StartPage: 114 Subjects: – SubjectFull: Computational fluid dynamics Type: general – SubjectFull: Fluidized bed reactors Type: general – SubjectFull: Hydrodynamics Type: general – SubjectFull: Energy dissipation Type: general – SubjectFull: Boundary value problems Type: general Titles: – TitleFull: On the limitations of 2D CFD for thin-rectangular fluidized bed simulations. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Bakshi, A. – PersonEntity: Name: NameFull: Altantzis, C. – PersonEntity: Name: NameFull: Bershanska, A. – PersonEntity: Name: NameFull: Stark, A.K. – PersonEntity: Name: NameFull: Ghoniem, A.F. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 00325910 Numbering: – Type: volume Value: 332 Titles: – TitleFull: Powder Technology Type: main |
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