Lagrangian coherent structures separate dynamically distinct regions in fluid flows
Using filter-space techniques, we study the scale-to-scale transport of energy in a quasi-two-dimensional, weakly turbulent fluid flow averaged along the trajectories of fluid elements. We find that although the spatial mean of this Lagrangian-averaged flux is nearly unchanged from its Eulerian coun...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2013
|
| Online Access: | http://hdl.handle.net/1721.1/81384 |
| _version_ | 1826217216545128448 |
|---|---|
| author | Kelley, Douglas H. Allshouse, Michael R. Ouellette, Nicholas T. |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Kelley, Douglas H. Allshouse, Michael R. Ouellette, Nicholas T. |
| author_sort | Kelley, Douglas H. |
| collection | MIT |
| description | Using filter-space techniques, we study the scale-to-scale transport of energy in a quasi-two-dimensional, weakly turbulent fluid flow averaged along the trajectories of fluid elements. We find that although the spatial mean of this Lagrangian-averaged flux is nearly unchanged from its Eulerian counterpart, the spatial structure of the scale-to-scale energy flux changes significantly. In particular, its features appear to correlate with the positions of Lagrangian coherent structures (LCS's). We show that the LCS's tend to lie at zeros of the scale-to-scale flux, and therefore that the LCS's separate regions that have qualitatively different dynamics. Since LCS's are also known to be impenetrable barriers to advection and mixing, we therefore find that the fluid on either side of an LCS is both kinematically and dynamically distinct. Our results extend the utility of LCS's by making clear the role they play in the flow dynamics in addition to the kinematics. |
| first_indexed | 2024-09-23T17:00:09Z |
| format | Article |
| id | mit-1721.1/81384 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T17:00:09Z |
| publishDate | 2013 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/813842022-09-29T22:59:23Z Lagrangian coherent structures separate dynamically distinct regions in fluid flows Kelley, Douglas H. Allshouse, Michael R. Ouellette, Nicholas T. Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Mechanical Engineering Kelley, Douglas H. Allshouse, Michael R. Using filter-space techniques, we study the scale-to-scale transport of energy in a quasi-two-dimensional, weakly turbulent fluid flow averaged along the trajectories of fluid elements. We find that although the spatial mean of this Lagrangian-averaged flux is nearly unchanged from its Eulerian counterpart, the spatial structure of the scale-to-scale energy flux changes significantly. In particular, its features appear to correlate with the positions of Lagrangian coherent structures (LCS's). We show that the LCS's tend to lie at zeros of the scale-to-scale flux, and therefore that the LCS's separate regions that have qualitatively different dynamics. Since LCS's are also known to be impenetrable barriers to advection and mixing, we therefore find that the fluid on either side of an LCS is both kinematically and dynamically distinct. Our results extend the utility of LCS's by making clear the role they play in the flow dynamics in addition to the kinematics. National Science Foundation (U.S.) (Grant DMR-0906245) National Science Foundation (U.S.) (Grant DMR-1206399) 2013-10-15T15:39:20Z 2013-10-15T15:39:20Z 2013-07 2012-09 Article http://purl.org/eprint/type/JournalArticle 1539-3755 1550-2376 http://hdl.handle.net/1721.1/81384 Kelley, Douglas H., Michael R. Allshouse, and Nicholas T. Ouellette. “Lagrangian Coherent Structures Separate Dynamically Distinct Regions in Fluid Flows.” Physical Review E 88.1 (2013). © 2013 American Physical Society en_US http://dx.doi.org/10.1103/PhysRevE.88.013017 Physical Review E Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society American Physical Society |
| spellingShingle | Kelley, Douglas H. Allshouse, Michael R. Ouellette, Nicholas T. Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title | Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title_full | Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title_fullStr | Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title_full_unstemmed | Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title_short | Lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| title_sort | lagrangian coherent structures separate dynamically distinct regions in fluid flows |
| url | http://hdl.handle.net/1721.1/81384 |
| work_keys_str_mv | AT kelleydouglash lagrangiancoherentstructuresseparatedynamicallydistinctregionsinfluidflows AT allshousemichaelr lagrangiancoherentstructuresseparatedynamicallydistinctregionsinfluidflows AT ouellettenicholast lagrangiancoherentstructuresseparatedynamicallydistinctregionsinfluidflows |