The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study
In rotary kilns in grate-kiln systems for iron ore pelletizing, a long and stable jet flame is needed to ensure a high quality of the pellets. The primary jet issuing from the nozzle interacts with two asymmetric co-flows creating a very complex flow. In order to better understand and eventually mod...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | International Journal of Chemical Engineering |
| Online Access: | http://dx.doi.org/10.1155/2018/1572576 |
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| author | Ziyan Teng I. A. Sofia Larsson T. Staffan Lundström B. Daniel Marjavaara |
| author_facet | Ziyan Teng I. A. Sofia Larsson T. Staffan Lundström B. Daniel Marjavaara |
| author_sort | Ziyan Teng |
| collection | DOAJ |
| description | In rotary kilns in grate-kiln systems for iron ore pelletizing, a long and stable jet flame is needed to ensure a high quality of the pellets. The primary jet issuing from the nozzle interacts with two asymmetric co-flows creating a very complex flow. In order to better understand and eventually model this flow with quality and trust, simplified cases need to be studied. In this work, a simplified and virtual model is built based on a down-scaled kiln model established in a previous experimental work. The aim is to numerically study the jet development as a function of position and Reynolds number (Re). The numerical simulations are carried out with the standard k-ε model, and quite accurate velocity profiles are obtained while the centerline decays and spreading of the passive scalars are over predicted. The model is capable of predicting a Re dependency of the jet development. With increasing Re, the jet is longer while it generally decays and spreads faster resulting from the stronger shear between the jet and co-flows and the stronger entrainment from the recirculation zone. This recirculation found in the simulations restrain the momentum spreading in the spanwise direction, leading to a slower velocity spreading with higher Re. For further validation and understanding, more measurements in the shear layer and simulations with more advanced turbulence models are necessary. |
| format | Article |
| id | doaj-art-d1a36902c78f467caa8e5bdc6d4bd8a2 |
| institution | Kabale University |
| issn | 1687-806X 1687-8078 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Chemical Engineering |
| spelling | doaj-art-d1a36902c78f467caa8e5bdc6d4bd8a22025-02-03T05:48:01ZengWileyInternational Journal of Chemical Engineering1687-806X1687-80782018-01-01201810.1155/2018/15725761572576The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD StudyZiyan Teng0I. A. Sofia Larsson1T. Staffan Lundström2B. Daniel Marjavaara3Division of Fluid and Experimental Mechanics, Luleå University of Technology, Luleå SE-971 87, SwedenDivision of Fluid and Experimental Mechanics, Luleå University of Technology, Luleå SE-971 87, SwedenDivision of Fluid and Experimental Mechanics, Luleå University of Technology, Luleå SE-971 87, SwedenLuossavaara-Kiirunavaara AB, Kiruna SE-981 86, SwedenIn rotary kilns in grate-kiln systems for iron ore pelletizing, a long and stable jet flame is needed to ensure a high quality of the pellets. The primary jet issuing from the nozzle interacts with two asymmetric co-flows creating a very complex flow. In order to better understand and eventually model this flow with quality and trust, simplified cases need to be studied. In this work, a simplified and virtual model is built based on a down-scaled kiln model established in a previous experimental work. The aim is to numerically study the jet development as a function of position and Reynolds number (Re). The numerical simulations are carried out with the standard k-ε model, and quite accurate velocity profiles are obtained while the centerline decays and spreading of the passive scalars are over predicted. The model is capable of predicting a Re dependency of the jet development. With increasing Re, the jet is longer while it generally decays and spreads faster resulting from the stronger shear between the jet and co-flows and the stronger entrainment from the recirculation zone. This recirculation found in the simulations restrain the momentum spreading in the spanwise direction, leading to a slower velocity spreading with higher Re. For further validation and understanding, more measurements in the shear layer and simulations with more advanced turbulence models are necessary.http://dx.doi.org/10.1155/2018/1572576 |
| spellingShingle | Ziyan Teng I. A. Sofia Larsson T. Staffan Lundström B. Daniel Marjavaara The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study International Journal of Chemical Engineering |
| title | The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study |
| title_full | The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study |
| title_fullStr | The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study |
| title_full_unstemmed | The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study |
| title_short | The Effect of Reynolds Number on Jet in Asymmetric Co-Flows: A CFD Study |
| title_sort | effect of reynolds number on jet in asymmetric co flows a cfd study |
| url | http://dx.doi.org/10.1155/2018/1572576 |
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