Eulerian spatio-temporal correlations in passive scalar turbulence
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2021
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866910579603537920 |
|---|---|
| author | Gorbunova, Anastasiia Pagani, Carlo Balarac, Guilaume Canet, Léonie Rossetto, Vincent |
| author_facet | Gorbunova, Anastasiia Pagani, Carlo Balarac, Guilaume Canet, Léonie Rossetto, Vincent |
| contents | We study the spatio-temporal two-point correlation function of passively advected scalar fields in the inertial-convective range in three dimensions by means of numerical simulations. We show that at small time delays $t$ the correlations decay as a Gaussian in the variable $tp$ where $p$ is the wavenumber. At large time delays, a crossover to an exponential decay in $tp^2$ is expected from a recent functional renormalization group (FRG) analysis. We study this regime for a scalar field advected by a Kraichnan's ``synthetic'' velocity field, and accurately confirm the FRG result, including the form of the prefactor in the exponential. By introducing finite time correlations in the synthetic velocity field, we uncover the crossover between the two regimes. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2104_12453 |
| institution | arXiv |
| publishDate | 2021 |
| record_format | arxiv |
| spellingShingle | Eulerian spatio-temporal correlations in passive scalar turbulence Gorbunova, Anastasiia Pagani, Carlo Balarac, Guilaume Canet, Léonie Rossetto, Vincent Fluid Dynamics Statistical Mechanics We study the spatio-temporal two-point correlation function of passively advected scalar fields in the inertial-convective range in three dimensions by means of numerical simulations. We show that at small time delays $t$ the correlations decay as a Gaussian in the variable $tp$ where $p$ is the wavenumber. At large time delays, a crossover to an exponential decay in $tp^2$ is expected from a recent functional renormalization group (FRG) analysis. We study this regime for a scalar field advected by a Kraichnan's ``synthetic'' velocity field, and accurately confirm the FRG result, including the form of the prefactor in the exponential. By introducing finite time correlations in the synthetic velocity field, we uncover the crossover between the two regimes. |
| title | Eulerian spatio-temporal correlations in passive scalar turbulence |
| topic | Fluid Dynamics Statistical Mechanics |
| url | https://arxiv.org/abs/2104.12453 |