Skip to Main content Skip to Navigation
Theses

Détection des grandes structures turbulentes dans les couches de mélange de type Rayleigh-Taylor en vue de la validation de modèles statistiques turbulents bi-structure

Abstract : This thesis aims at detecting large-scale turbulent structures in incompressible Rayleigh-Taylor mixing layers at low Atwood number. Various statistical quantities conditioned by structure presence have been obtained and it is now possible to compare them with results from two-structure statistical turbulent models such as the 2SFK model developed at CEA. In order to produce direct numerical simulations of the turbulent mixing, a three-dimensional, incompressible, variable-density numerical code was developed. This code is parallelized in the three directions. Several structure detection methods have been designed and tested. Although all these methods are of interest, only the most efficient with respect to our detection criteria has been retained for simulations at high resolution (over a billion cells, 1024^3). A time filtering of vertical velocity is used in this method to: 1) correct distortions due to stagnation points and recirculation zones in the flow, 2) minimize small-scale turbulence effects and better highlight large-scales, 3) introduce a memory effect in order to extend bimodality of the detection field from the external laminar zones up to the centre of the turbulent mixing zone. Several direct numerical simulations at 1024^3 have been achieved. Results support those obtained with two-structure 2SFK model and justify further studies for its validation.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00669707
Contributor : Abes Star :  Contact
Submitted on : Monday, February 13, 2012 - 5:03:10 PM
Last modification on : Friday, October 23, 2020 - 5:03:35 PM
Long-term archiving on: : Monday, May 14, 2012 - 2:50:21 AM

File

Watteaux2011.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00669707, version 1

Collections

Citation

Romain Watteaux. Détection des grandes structures turbulentes dans les couches de mélange de type Rayleigh-Taylor en vue de la validation de modèles statistiques turbulents bi-structure. Mathématiques générales [math.GM]. École normale supérieure de Cachan - ENS Cachan, 2011. Français. ⟨NNT : 2011DENS0035⟩. ⟨tel-00669707⟩

Share

Metrics

Record views

783

Files downloads

471