Asymptotic states of decaying turbulence in two-dimensional incompressible flows

We investigate the relaxation of a strongly turbulent fluid to metastable states, in times much shorter than the dissipation time scale. Several simulations of decaying two-dimensional Navier-Stokes flows were performed, which show the relaxation to organized states dominated by coherent vortex stru...

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Detalles Bibliográficos
Autores principales: Dmitruk, Pablo Ariel, Gomez, Daniel Osvaldo, Ponce Dawson, Silvina
Publicado: 1996
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1063651X_v54_n3_p2555_Dmitruk
http://hdl.handle.net/20.500.12110/paper_1063651X_v54_n3_p2555_Dmitruk
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_1063651X_v54_n3_p2555_Dmitruk
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spelling paper:paper_1063651X_v54_n3_p2555_Dmitruk2023-06-08T16:03:35Z Asymptotic states of decaying turbulence in two-dimensional incompressible flows Dmitruk, Pablo Ariel Gomez, Daniel Osvaldo Ponce Dawson, Silvina We investigate the relaxation of a strongly turbulent fluid to metastable states, in times much shorter than the dissipation time scale. Several simulations of decaying two-dimensional Navier-Stokes flows were performed, which show the relaxation to organized states dominated by coherent vortex structures of length scales comparable to the size of the system. In the case of periodic boundary conditions, the organized state is characterized by a strong correlation between vorticity and stream function, the second of which satisfies a sinh-Poisson equation quite accurately. However, in the case of free-slip boundary conditions the relaxed state does not display any significant correlation between its vorticity and its stream function. Notwithstanding, in both cases the role of nonlinearities is found to be essential even at these late stages of the evolution. However, we show that even severe truncations of a few (short wave number) nonlinearly coupled Fourier modes provide an accurate description of the long-term dynamics of the fluid. Therefore the dynamics of the flow in these metastable states is somewhere in between a strong turbulent regime and a (mostly linear) dissipative relaxation stage. © 1996 The American Physical Society. Fil:Dmitruk, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gómez, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Dawson, S.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1996 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1063651X_v54_n3_p2555_Dmitruk http://hdl.handle.net/20.500.12110/paper_1063651X_v54_n3_p2555_Dmitruk
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description We investigate the relaxation of a strongly turbulent fluid to metastable states, in times much shorter than the dissipation time scale. Several simulations of decaying two-dimensional Navier-Stokes flows were performed, which show the relaxation to organized states dominated by coherent vortex structures of length scales comparable to the size of the system. In the case of periodic boundary conditions, the organized state is characterized by a strong correlation between vorticity and stream function, the second of which satisfies a sinh-Poisson equation quite accurately. However, in the case of free-slip boundary conditions the relaxed state does not display any significant correlation between its vorticity and its stream function. Notwithstanding, in both cases the role of nonlinearities is found to be essential even at these late stages of the evolution. However, we show that even severe truncations of a few (short wave number) nonlinearly coupled Fourier modes provide an accurate description of the long-term dynamics of the fluid. Therefore the dynamics of the flow in these metastable states is somewhere in between a strong turbulent regime and a (mostly linear) dissipative relaxation stage. © 1996 The American Physical Society.
author Dmitruk, Pablo Ariel
Gomez, Daniel Osvaldo
Ponce Dawson, Silvina
spellingShingle Dmitruk, Pablo Ariel
Gomez, Daniel Osvaldo
Ponce Dawson, Silvina
Asymptotic states of decaying turbulence in two-dimensional incompressible flows
author_facet Dmitruk, Pablo Ariel
Gomez, Daniel Osvaldo
Ponce Dawson, Silvina
author_sort Dmitruk, Pablo Ariel
title Asymptotic states of decaying turbulence in two-dimensional incompressible flows
title_short Asymptotic states of decaying turbulence in two-dimensional incompressible flows
title_full Asymptotic states of decaying turbulence in two-dimensional incompressible flows
title_fullStr Asymptotic states of decaying turbulence in two-dimensional incompressible flows
title_full_unstemmed Asymptotic states of decaying turbulence in two-dimensional incompressible flows
title_sort asymptotic states of decaying turbulence in two-dimensional incompressible flows
publishDate 1996
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1063651X_v54_n3_p2555_Dmitruk
http://hdl.handle.net/20.500.12110/paper_1063651X_v54_n3_p2555_Dmitruk
work_keys_str_mv AT dmitrukpabloariel asymptoticstatesofdecayingturbulenceintwodimensionalincompressibleflows
AT gomezdanielosvaldo asymptoticstatesofdecayingturbulenceintwodimensionalincompressibleflows
AT poncedawsonsilvina asymptoticstatesofdecayingturbulenceintwodimensionalincompressibleflows
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