Inner-outer decomposition of wall shear stress fluctuations in turbulent channels
Fluctuating wall shear stress in turbulent channel flows is decomposed into small-scale and large-scale components. The large-scale fluctuating wall shear stress is computed as the footprints of the outer turbulent motions, and the small-scale one is obtained by subtracting the large-scale one from...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-02-01
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| Series: | Theoretical and Applied Mechanics Letters |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2095034922000174 |
| _version_ | 1828791840186302464 |
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| author | Limin Wang Ruifeng Hu |
| author_facet | Limin Wang Ruifeng Hu |
| author_sort | Limin Wang |
| collection | DOAJ |
| description | Fluctuating wall shear stress in turbulent channel flows is decomposed into small-scale and large-scale components. The large-scale fluctuating wall shear stress is computed as the footprints of the outer turbulent motions, and the small-scale one is obtained by subtracting the large-scale one from the total, which fully remove the outer influences. We show that the statistics of the small-scale fluctuating wall shear stress is Reynolds number independent at the friction Reynolds number larger than 1000, while which is Reynolds number dependent or the low-Reynolds-number effect exists at the friction Reynolds number smaller than 1000. Therefore, a critical Reynolds number that defines the emergence of universal small-scale fluctuating wall shear stress is proposed to be 1000. The total and large-scale fluctuating wall shear stress intensities approximately follow logarithmic-linear relationships with Reynolds number, and empirical fitting expressions are given in this work. |
| first_indexed | 2024-12-12T02:57:34Z |
| format | Article |
| id | doaj.art-6759b3f265a640329ce86e296e7df446 |
| institution | Directory Open Access Journal |
| issn | 2095-0349 |
| language | English |
| last_indexed | 2024-12-12T02:57:34Z |
| publishDate | 2022-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Theoretical and Applied Mechanics Letters |
| spelling | doaj.art-6759b3f265a640329ce86e296e7df4462022-12-22T00:40:41ZengElsevierTheoretical and Applied Mechanics Letters2095-03492022-02-01122100337Inner-outer decomposition of wall shear stress fluctuations in turbulent channelsLimin Wang0Ruifeng Hu1Center for Particle-Laden Turbulence, Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, ChinaCorresponding author.; Center for Particle-Laden Turbulence, Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, ChinaFluctuating wall shear stress in turbulent channel flows is decomposed into small-scale and large-scale components. The large-scale fluctuating wall shear stress is computed as the footprints of the outer turbulent motions, and the small-scale one is obtained by subtracting the large-scale one from the total, which fully remove the outer influences. We show that the statistics of the small-scale fluctuating wall shear stress is Reynolds number independent at the friction Reynolds number larger than 1000, while which is Reynolds number dependent or the low-Reynolds-number effect exists at the friction Reynolds number smaller than 1000. Therefore, a critical Reynolds number that defines the emergence of universal small-scale fluctuating wall shear stress is proposed to be 1000. The total and large-scale fluctuating wall shear stress intensities approximately follow logarithmic-linear relationships with Reynolds number, and empirical fitting expressions are given in this work.http://www.sciencedirect.com/science/article/pii/S2095034922000174Turbulent boundary layerWall shear stressInner-outer decomposition |
| spellingShingle | Limin Wang Ruifeng Hu Inner-outer decomposition of wall shear stress fluctuations in turbulent channels Theoretical and Applied Mechanics Letters Turbulent boundary layer Wall shear stress Inner-outer decomposition |
| title | Inner-outer decomposition of wall shear stress fluctuations in turbulent channels |
| title_full | Inner-outer decomposition of wall shear stress fluctuations in turbulent channels |
| title_fullStr | Inner-outer decomposition of wall shear stress fluctuations in turbulent channels |
| title_full_unstemmed | Inner-outer decomposition of wall shear stress fluctuations in turbulent channels |
| title_short | Inner-outer decomposition of wall shear stress fluctuations in turbulent channels |
| title_sort | inner outer decomposition of wall shear stress fluctuations in turbulent channels |
| topic | Turbulent boundary layer Wall shear stress Inner-outer decomposition |
| url | http://www.sciencedirect.com/science/article/pii/S2095034922000174 |
| work_keys_str_mv | AT liminwang innerouterdecompositionofwallshearstressfluctuationsinturbulentchannels AT ruifenghu innerouterdecompositionofwallshearstressfluctuationsinturbulentchannels |