On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method
In the present paper, the energy gradient method is implemented to study the instability of 2-D laminar backward-facing step (BFS) flow under different Reynolds numbers and expansion ratios. For this purpose, six different Reynolds numbers (50 ≤ Re ≤ 1000) and two various expansion ratios of 1.9423...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Isfahan University of Technology
2018-01-01
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| Series: | Journal of Applied Fluid Mechanics |
| Subjects: | |
| Online Access: | http://jafmonline.net/JournalArchive/download?file_ID=44268&issue_ID=246 |
| _version_ | 1818207603624247296 |
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| author | H. Nowruzi S. Salman Nourazar H. Ghassemi |
| author_facet | H. Nowruzi S. Salman Nourazar H. Ghassemi |
| author_sort | H. Nowruzi |
| collection | DOAJ |
| description | In the present paper, the energy gradient method is implemented to study the instability of 2-D laminar backward-facing step (BFS) flow under different Reynolds numbers and expansion ratios. For this purpose, six different Reynolds numbers (50 ≤ Re ≤ 1000) and two various expansion ratios of 1.9423 and 3 are considered. We compared our results of the present study with existing experimental and numerical data and good agreement is achieved. To study of fluid flow instability, we evaluated the distributions of velocity, vorticity and energy gradient function K. The results of our study show that as the expansion ratio decreases the flow becomes more stable. We also found that the origin of instability in the entire flow field is located on the separated shear layer nearby the step edge. In addition, we approved that the inflection point on the profile of velocity corresponds to the maximum of vorticity resulted to the instability. |
| first_indexed | 2024-12-12T04:31:33Z |
| format | Article |
| id | doaj.art-58506f8f96de4608a209fececc231768 |
| institution | Directory Open Access Journal |
| issn | 1735-3572 |
| language | English |
| last_indexed | 2024-12-12T04:31:33Z |
| publishDate | 2018-01-01 |
| publisher | Isfahan University of Technology |
| record_format | Article |
| series | Journal of Applied Fluid Mechanics |
| spelling | doaj.art-58506f8f96de4608a209fececc2317682022-12-22T00:38:04ZengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722018-01-01111241256.On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient MethodH. Nowruzi0S. Salman Nourazar1H. Ghassemi2Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Tehran, IranDepartment of Mechanical Engineering, Amirkabir University of Technology, Tehran, IranDepartment of Maritime Engineering, Amirkabir University of Technology, Tehran, Tehran, IranIn the present paper, the energy gradient method is implemented to study the instability of 2-D laminar backward-facing step (BFS) flow under different Reynolds numbers and expansion ratios. For this purpose, six different Reynolds numbers (50 ≤ Re ≤ 1000) and two various expansion ratios of 1.9423 and 3 are considered. We compared our results of the present study with existing experimental and numerical data and good agreement is achieved. To study of fluid flow instability, we evaluated the distributions of velocity, vorticity and energy gradient function K. The results of our study show that as the expansion ratio decreases the flow becomes more stable. We also found that the origin of instability in the entire flow field is located on the separated shear layer nearby the step edge. In addition, we approved that the inflection point on the profile of velocity corresponds to the maximum of vorticity resulted to the instability.http://jafmonline.net/JournalArchive/download?file_ID=44268&issue_ID=246Energy gradient; Instability; Backward-facing step flow. |
| spellingShingle | H. Nowruzi S. Salman Nourazar H. Ghassemi On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method Journal of Applied Fluid Mechanics Energy gradient; Instability; Backward-facing step flow. |
| title | On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method |
| title_full | On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method |
| title_fullStr | On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method |
| title_full_unstemmed | On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method |
| title_short | On the Instability of Two Dimensional Backward-Facing Step Flow using Energy Gradient Method |
| title_sort | on the instability of two dimensional backward facing step flow using energy gradient method |
| topic | Energy gradient; Instability; Backward-facing step flow. |
| url | http://jafmonline.net/JournalArchive/download?file_ID=44268&issue_ID=246 |
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