Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows
Axial segregation of polydisperse granular mixtures in rotating drums have been observed in several experimental and discrete particle simulation studies reported in the literature. A common thread to both experimental and numerical studies is the formation of (alternating) bands which eventually co...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/11/9/915 |
| _version_ | 1797518070573432832 |
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| author | Elbasher Mohamed Elbasher Ahmed Indresan Govender Aubrey Njema Mainza |
| author_facet | Elbasher Mohamed Elbasher Ahmed Indresan Govender Aubrey Njema Mainza |
| author_sort | Elbasher Mohamed Elbasher Ahmed |
| collection | DOAJ |
| description | Axial segregation of polydisperse granular mixtures in rotating drums have been observed in several experimental and discrete particle simulation studies reported in the literature. A common thread to both experimental and numerical studies is the formation of (alternating) bands which eventually coarsen in the long-time limit due to logarithmic merging. Models to explain the experimental observations are generally limited to bidisperse mixtures, and often unable to reproduce band coarsening. One such mechanism for bidisperse mixtures argues that the grains eventually diffuse into axial bands as a consequence of concentration fluctuations in the free surface layer caused by friction-limited mobility. We generalise this model to multi-species mixtures and show that the solution produces banding that evolves more complexly than binary mixtures, with sinusoidal-like variations of the band structure that evolves non-linearly in time. In addition, we successfully recover band coarsening with time—an observation that is generally difficult to reproduce, even experimentally. Contrary to literature findings, the configurations herein did not produce bands within bands for ternary and quaternary mixtures. |
| first_indexed | 2024-03-10T07:25:02Z |
| format | Article |
| id | doaj.art-523225aa2f014e4bb0dbcb42eb632124 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T07:25:02Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-523225aa2f014e4bb0dbcb42eb6321242023-11-22T14:20:28ZengMDPI AGMinerals2075-163X2021-08-0111991510.3390/min11090915Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum FlowsElbasher Mohamed Elbasher Ahmed0Indresan Govender1Aubrey Njema Mainza2Department of Chemical Engineering, University of KwaZulu-Natal, Glenwood 4041, South AfricaDepartment of Chemical Engineering, University of KwaZulu-Natal, Glenwood 4041, South AfricaCentre for Minerals Research, University of Cape Town, Cape Town 7701, South AfricaAxial segregation of polydisperse granular mixtures in rotating drums have been observed in several experimental and discrete particle simulation studies reported in the literature. A common thread to both experimental and numerical studies is the formation of (alternating) bands which eventually coarsen in the long-time limit due to logarithmic merging. Models to explain the experimental observations are generally limited to bidisperse mixtures, and often unable to reproduce band coarsening. One such mechanism for bidisperse mixtures argues that the grains eventually diffuse into axial bands as a consequence of concentration fluctuations in the free surface layer caused by friction-limited mobility. We generalise this model to multi-species mixtures and show that the solution produces banding that evolves more complexly than binary mixtures, with sinusoidal-like variations of the band structure that evolves non-linearly in time. In addition, we successfully recover band coarsening with time—an observation that is generally difficult to reproduce, even experimentally. Contrary to literature findings, the configurations herein did not produce bands within bands for ternary and quaternary mixtures.https://www.mdpi.com/2075-163X/11/9/915segregation modellingmultiple speciesbandingcoarseningfrictionmobility |
| spellingShingle | Elbasher Mohamed Elbasher Ahmed Indresan Govender Aubrey Njema Mainza Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows Minerals segregation modelling multiple species banding coarsening friction mobility |
| title | Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows |
| title_full | Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows |
| title_fullStr | Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows |
| title_full_unstemmed | Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows |
| title_short | Axial Segregation of Polydisperse Granular Mixtures in Rotating Drum Flows |
| title_sort | axial segregation of polydisperse granular mixtures in rotating drum flows |
| topic | segregation modelling multiple species banding coarsening friction mobility |
| url | https://www.mdpi.com/2075-163X/11/9/915 |
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