Effects of mean shear on the vortex identification and the orientation statistics
This work compares the threshold applied to the swirling strength as well as the vortex orientation statistics in the total and fluctuating velocity fields using direct numerical simulations of compressible and incompressible turbulent channel flows. It is concluded that the difference in the swirli...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-07-01
|
| Series: | Theoretical and Applied Mechanics Letters |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2095034923000259 |
| _version_ | 1797635383133995008 |
|---|---|
| author | Tianyi Bai Cheng Cheng Lin Fu |
| author_facet | Tianyi Bai Cheng Cheng Lin Fu |
| author_sort | Tianyi Bai |
| collection | DOAJ |
| description | This work compares the threshold applied to the swirling strength as well as the vortex orientation statistics in the total and fluctuating velocity fields using direct numerical simulations of compressible and incompressible turbulent channel flows. It is concluded that the difference in the swirling strength for vortex identification is minimal in the logarithmic region such that these two situations share the same threshold. Regarding the vortex orientation, the inclination angle remains similar. However, as the wall-normal distance increases, a more and more obvious distinction is noticed for its orientation with respect to the spanwise (z) direction. It is mainly due to their intrinsic differences and attendant contrasting preference for the vortex identification, i.e., vortices rotating in the −z direction for the total velocity field and in the z direction for the fluctuating one. These observations function as a reasonable explanation for various remarks in previous studies. |
| first_indexed | 2024-03-11T12:20:20Z |
| format | Article |
| id | doaj.art-f44ae958cf564b6191347d4c269c4836 |
| institution | Directory Open Access Journal |
| issn | 2095-0349 |
| language | English |
| last_indexed | 2024-03-11T12:20:20Z |
| publishDate | 2023-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Theoretical and Applied Mechanics Letters |
| spelling | doaj.art-f44ae958cf564b6191347d4c269c48362023-11-07T04:02:27ZengElsevierTheoretical and Applied Mechanics Letters2095-03492023-07-01134100454Effects of mean shear on the vortex identification and the orientation statisticsTianyi Bai0Cheng Cheng1Lin Fu2Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, ChinaDepartment of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, ChinaCorresponding author.; Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; Department of Mathematics, The Hong Kong University of Science and Technology, Hong Kong 999077, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen 815057, ChinaThis work compares the threshold applied to the swirling strength as well as the vortex orientation statistics in the total and fluctuating velocity fields using direct numerical simulations of compressible and incompressible turbulent channel flows. It is concluded that the difference in the swirling strength for vortex identification is minimal in the logarithmic region such that these two situations share the same threshold. Regarding the vortex orientation, the inclination angle remains similar. However, as the wall-normal distance increases, a more and more obvious distinction is noticed for its orientation with respect to the spanwise (z) direction. It is mainly due to their intrinsic differences and attendant contrasting preference for the vortex identification, i.e., vortices rotating in the −z direction for the total velocity field and in the z direction for the fluctuating one. These observations function as a reasonable explanation for various remarks in previous studies.http://www.sciencedirect.com/science/article/pii/S2095034923000259VortexCompressible wall-bounded turbulenceTurbulence structureChannel flows |
| spellingShingle | Tianyi Bai Cheng Cheng Lin Fu Effects of mean shear on the vortex identification and the orientation statistics Theoretical and Applied Mechanics Letters Vortex Compressible wall-bounded turbulence Turbulence structure Channel flows |
| title | Effects of mean shear on the vortex identification and the orientation statistics |
| title_full | Effects of mean shear on the vortex identification and the orientation statistics |
| title_fullStr | Effects of mean shear on the vortex identification and the orientation statistics |
| title_full_unstemmed | Effects of mean shear on the vortex identification and the orientation statistics |
| title_short | Effects of mean shear on the vortex identification and the orientation statistics |
| title_sort | effects of mean shear on the vortex identification and the orientation statistics |
| topic | Vortex Compressible wall-bounded turbulence Turbulence structure Channel flows |
| url | http://www.sciencedirect.com/science/article/pii/S2095034923000259 |
| work_keys_str_mv | AT tianyibai effectsofmeanshearonthevortexidentificationandtheorientationstatistics AT chengcheng effectsofmeanshearonthevortexidentificationandtheorientationstatistics AT linfu effectsofmeanshearonthevortexidentificationandtheorientationstatistics |