Enhanced inverse-cascade of energy in the averaged Euler equations
For a particular choice of the smoothing kernel, it is shown that the system of partial differential equations governing the vortex-blob method corresponds to the averaged Euler equations. These latter equations have recently been derived by averaging the Euler equations over Lagrangian fluctuations...
| Main Authors: | , |
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| Format: | Journal article |
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2000
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| _version_ | 1797053348908630016 |
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| author | Nadiga, B Shkoller, S |
| author_facet | Nadiga, B Shkoller, S |
| author_sort | Nadiga, B |
| collection | OXFORD |
| description | For a particular choice of the smoothing kernel, it is shown that the system of partial differential equations governing the vortex-blob method corresponds to the averaged Euler equations. These latter equations have recently been derived by averaging the Euler equations over Lagrangian fluctuations of length scale $\a$, and the same system is also encountered in the description of inviscid and incompressible flow of second-grade polymeric (non-Newtonian) fluids. While previous studies of this system have noted the suppression of nonlinear interaction between modes smaller than $\a$, we show that the modification of the nonlinear advection term also acts to enhance the inverse-cascade of energy in two-dimensional turbulence and thereby affects scales of motion larger than $\a$ as well. This latter effect is reminiscent of the drag-reduction that occurs in a turbulent flow when a dilute polymer is added. |
| first_indexed | 2024-03-06T18:42:35Z |
| format | Journal article |
| id | oxford-uuid:0d678a1e-f01f-4961-ab27-7a428d627363 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T18:42:35Z |
| publishDate | 2000 |
| record_format | dspace |
| spelling | oxford-uuid:0d678a1e-f01f-4961-ab27-7a428d6273632022-03-26T09:40:19ZEnhanced inverse-cascade of energy in the averaged Euler equationsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0d678a1e-f01f-4961-ab27-7a428d627363Symplectic Elements at Oxford2000Nadiga, BShkoller, SFor a particular choice of the smoothing kernel, it is shown that the system of partial differential equations governing the vortex-blob method corresponds to the averaged Euler equations. These latter equations have recently been derived by averaging the Euler equations over Lagrangian fluctuations of length scale $\a$, and the same system is also encountered in the description of inviscid and incompressible flow of second-grade polymeric (non-Newtonian) fluids. While previous studies of this system have noted the suppression of nonlinear interaction between modes smaller than $\a$, we show that the modification of the nonlinear advection term also acts to enhance the inverse-cascade of energy in two-dimensional turbulence and thereby affects scales of motion larger than $\a$ as well. This latter effect is reminiscent of the drag-reduction that occurs in a turbulent flow when a dilute polymer is added. |
| spellingShingle | Nadiga, B Shkoller, S Enhanced inverse-cascade of energy in the averaged Euler equations |
| title | Enhanced inverse-cascade of energy in the averaged Euler equations |
| title_full | Enhanced inverse-cascade of energy in the averaged Euler equations |
| title_fullStr | Enhanced inverse-cascade of energy in the averaged Euler equations |
| title_full_unstemmed | Enhanced inverse-cascade of energy in the averaged Euler equations |
| title_short | Enhanced inverse-cascade of energy in the averaged Euler equations |
| title_sort | enhanced inverse cascade of energy in the averaged euler equations |
| work_keys_str_mv | AT nadigab enhancedinversecascadeofenergyintheaveragedeulerequations AT shkollers enhancedinversecascadeofenergyintheaveragedeulerequations |