On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake
In this work, we numerically study the structure of the turbulent/nonturbulent (T/NT) interface in a fully developed spatially evolving axisymmetric wake by means of direct numerical simulations. There is a continuous and contorted pure shear layer (PSL) adjacent to the outer edge of the T/NT interf...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-03-01
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| Series: | Theoretical and Applied Mechanics Letters |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2095034922000848 |
| _version_ | 1797857675404378112 |
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| author | Weijun Yin YuanLiang Xie Xinxian Zhang Yi Zhou |
| author_facet | Weijun Yin YuanLiang Xie Xinxian Zhang Yi Zhou |
| author_sort | Weijun Yin |
| collection | DOAJ |
| description | In this work, we numerically study the structure of the turbulent/nonturbulent (T/NT) interface in a fully developed spatially evolving axisymmetric wake by means of direct numerical simulations. There is a continuous and contorted pure shear layer (PSL) adjacent to the outer edge of the T/NT interface. The local thickness of the PSL δPSL exhibits a wide range of scales (from the Kolmogorov scale to the Taylor microscale) and the conditional mean thickness 〈δPSL〉I/ηc≈6 with ηc being the centerline Kolmogorov scale is the same as the viscous superlayer. In the viscous superlayer, the pure shear motions without rotation are overwhelmingly dominant. It is also demonstrated that the physics of the turbulent sublayer is closely related to the PSL with a large thickness. Another significant finding is that the time averaged area of the rotational region 〈AR〉, and the pure shear region 〈AS〉 at different streamwise locations scale with the square of the wake-width bU2. This study opens an avenue for a better understanding of the structures of the T/NT interface. |
| first_indexed | 2024-04-09T21:00:37Z |
| format | Article |
| id | doaj.art-3f7d887c6f5f4620b4dcbee6725d70d7 |
| institution | Directory Open Access Journal |
| issn | 2095-0349 |
| language | English |
| last_indexed | 2024-04-09T21:00:37Z |
| publishDate | 2023-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Theoretical and Applied Mechanics Letters |
| spelling | doaj.art-3f7d887c6f5f4620b4dcbee6725d70d72023-03-29T09:25:58ZengElsevierTheoretical and Applied Mechanics Letters2095-03492023-03-01132100404On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wakeWeijun Yin0YuanLiang Xie1Xinxian Zhang2Yi Zhou3School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, ChinaSchool of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, ChinaFluid Mechanics Key Laboratory of Education Ministry, Beihang University, Beijing 100191, ChinaCorresponding author.; School of Energy and Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, ChinaIn this work, we numerically study the structure of the turbulent/nonturbulent (T/NT) interface in a fully developed spatially evolving axisymmetric wake by means of direct numerical simulations. There is a continuous and contorted pure shear layer (PSL) adjacent to the outer edge of the T/NT interface. The local thickness of the PSL δPSL exhibits a wide range of scales (from the Kolmogorov scale to the Taylor microscale) and the conditional mean thickness 〈δPSL〉I/ηc≈6 with ηc being the centerline Kolmogorov scale is the same as the viscous superlayer. In the viscous superlayer, the pure shear motions without rotation are overwhelmingly dominant. It is also demonstrated that the physics of the turbulent sublayer is closely related to the PSL with a large thickness. Another significant finding is that the time averaged area of the rotational region 〈AR〉, and the pure shear region 〈AS〉 at different streamwise locations scale with the square of the wake-width bU2. This study opens an avenue for a better understanding of the structures of the T/NT interface.http://www.sciencedirect.com/science/article/pii/S2095034922000848T/NT interfacePure shear motionViscous superlayerAxisymmetric wake |
| spellingShingle | Weijun Yin YuanLiang Xie Xinxian Zhang Yi Zhou On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake Theoretical and Applied Mechanics Letters T/NT interface Pure shear motion Viscous superlayer Axisymmetric wake |
| title | On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake |
| title_full | On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake |
| title_fullStr | On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake |
| title_full_unstemmed | On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake |
| title_short | On the structure of the turbulent/non-turbulent interface in a fully developed spatially evolving axisymmetric wake |
| title_sort | on the structure of the turbulent non turbulent interface in a fully developed spatially evolving axisymmetric wake |
| topic | T/NT interface Pure shear motion Viscous superlayer Axisymmetric wake |
| url | http://www.sciencedirect.com/science/article/pii/S2095034922000848 |
| work_keys_str_mv | AT weijunyin onthestructureoftheturbulentnonturbulentinterfaceinafullydevelopedspatiallyevolvingaxisymmetricwake AT yuanliangxie onthestructureoftheturbulentnonturbulentinterfaceinafullydevelopedspatiallyevolvingaxisymmetricwake AT xinxianzhang onthestructureoftheturbulentnonturbulentinterfaceinafullydevelopedspatiallyevolvingaxisymmetricwake AT yizhou onthestructureoftheturbulentnonturbulentinterfaceinafullydevelopedspatiallyevolvingaxisymmetricwake |