Instabilité, turbulence et contrôle

Aerodynamics

Biological fluid flows (pulmonary and cardiovascular)

Flows for magnetic fusion - ITER

Hydrodynamics and wall transfers

suite...

Instability, turbulence and control Team
Présentation

The ITC team develops expertise in numerical simulation and predictive analysis of flows in a lot of application areas focused on aeronautics, fusion, lung flows and hydrodynamic transfers. Innovative and optimized numerical methods are developed to address fundamental scientific issues, industrial applications, and current societal problems.
The team currently includes 12 researchers and is structured around 4 research axes :

Responsable

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Annuaire personnel permanent

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Doctorants, Post-Doctorants et CDD

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Dernières publications de l'équipe

  • M. Nguyen, J. Boussuge, P. Sagaut, J. Larroya-Huguet. Large eddy simulation of a thermal impinging jet using the lattice Boltzmann method. Physics of Fluids, American Institute of Physics, 2022, 34 (5), pp.055115. ⟨10.1063/5.0088410⟩. ⟨hal-03669901⟩ Plus de détails...
  • Rouae Ben Dhia, Nils Tilton, Denis Martinand. Impact of osmotic pressure on the stability of Taylor vortices. Journal of Fluid Mechanics, Cambridge University Press (CUP), 2022, 933, pp.A51. ⟨10.1017/jfm.2021.1101⟩. ⟨hal-03533753⟩ Plus de détails...
  • X Litaudon, F Jenko, D Borba, D Borodin, B J Braams, et al.. EUROfusion-theory and advanced simulation coordination (E-TASC): programme and the role of high performance computing. Plasma Physics and Controlled Fusion, IOP Publishing, 2022, 64 (3), pp.034005. ⟨10.1088/1361-6587/ac44e4⟩. ⟨hal-03562886⟩ Plus de détails...
  • D. Galassi, C. Theiler, T. Body, F. Manke, P. Micheletti, et al.. Validation of edge turbulence codes in a magnetic X-point scenario in TORPEX. Physics of Plasmas, American Institute of Physics, 2022, 29 (1), pp.012501. ⟨10.1063/5.0064522⟩. ⟨hal-03566373⟩ Plus de détails...
  • M Scotto d'Abusco, G Giorgiani, J F Artaud, H Bufferand, G Ciraolo, et al.. Core-edge 2D fluid modeling of full tokamak discharge with varying magnetic equilibrium: from WEST start-up to ramp-down. Nuclear Fusion, IOP Publishing, 2022, ⟨10.1088/1741-4326/ac47ad⟩. ⟨hal-03509800⟩ Plus de détails...
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Dernières rencontres scientifiques

Soutenances de thèses et HDR

7 novembre 2022 - Novel and efficient algorithms for the numerical simulation ofimmersed moving and deforming structures in realistic industrial conditions in aeronautics using lattice Boltzmann method / PhD defense Heesik YOO
Doctorant : Heesik YOO

Date : Monday 7 Novembre 2022 à 14:00 

Abstract : Rotating geometries are crucial configurations in industry, encountered in rotors, propellers and turbofans and the most classical method to simulate them in general computational fluid dynamics (CFD) is the overset mesh (so called, Chimera mesh), which uses two different meshes simultaneously. However the numerical complexity of this scheme makes their implementation challenging in CFD, not to mention in lattice Boltzmann method (LBM). LBM has been attracting several industrial sectors over the last decades, including aeronautical transport, energy and health, and still remains a very active research topic in CFD. While chronic drawbacks of the LBM have been being overcome recently by the community, such as the instability issues at high Reynolds and high Mach numbers, one of the major remaining challenges is to simulate with a high level of reliability rotating geometries undergoing these challenging industrial conditions. In this thesis, we provide a detailed study of the application of rotating overset grids in LBM at high Reynolds and high Mach numbers flows. To do so, since there exist both fixed and rotating meshes at the same time, an efficient interpolation procedure is used to perform the instantaneous communication between fixed and rotating meshes, and appropriate fictitious forces are applied in the rotating region to account for the non-inertial reference axis. Also, flow physics are described by hybrid recursive regularized LBM model (HRR), which is chosen to stabilize flow from high Reynolds, high Mach flow and the numerical defects of overset grids. Particularly, for compressible flow, temperature is transported by the entropy equation which solved by the MUSCL-Hancock scheme. The numerical framework is thoroughly analyzed by separating all numerical ingredients and by studying the different numerical error sources originated from the algorithm. It is validated on different test cases, from academic ones to challenging industrial ones. The results point out good accuracy and robustness of the numerical method compared to conventional finite volume Navier-Stokes solvers and experiments. According to the best of the author's knowledge, this work presents the first thorough validation and error analysis of the lattice Boltzmann method for simulating moving geometries in high Mach compressible flows, including any type of movement such as oscillation, translation and rotation, etc. 

Jury :
Directeur de these  M. Julien FAVIER  Aix Marseille Université
Rapporteur  M. Mathias KRAUSE  Karlsruhe Institute of Technology (KIT)
Rapporteur  M. Emmanuel LéVêQUE  LMFA Ecole Centrale Lyon
Président  Mme Berengere PODVIN  EM2C Centrale Superlec
Examinateur  M. Martin GEIER  TU-Braunschweig
CoDirecteur de these  M. Pierre SAGAUT  Aix Marseille Université
17 octobre 2022 - Optimization of bronchial decongestion by pressure wave thanks to CFD / PhD defense Antoine GALKO
Doctorant : Antoine GALKO

Date : Lundi 17 Octobre 2022 à 14:00 ; amphi 3, Centrale Marseille

Abstract : Lung diseases are affecting more and more people worldwide. The most common diseases are COPD, asthma and mucovisidosis. Patients suffering from these diseases often have dysfunctions in mucociliary clearance. Mucociliary clearance normally removes contaminated mucus from the bronchial tree. When there is a dysfunction, the mucus increases in quantity and usually becomes very viscous and sticky, making it difficult to clear. This increases the risk of lung infection. To limit and facilitate the life of the patients, devices of assistance to the bronchial désencombrement are developed like the SIMEOX® developed by the compagny Physio-Assist. This device uses periodic depressions to liquefy mucus in order to facilitate its expectoration. It is in this context that this thesis is conducted. To understand the impact of this type of device on bronchial clearance and more particularly on the rheology of mucus, a numerical study, using a lattice-Boltzmann method coupled with immersed boundaries, is carried out. The impact of a pressure forcing on a non-Newtonian fluid of the Herschel-Bulkley type is then studied. First, we consider a non-Newtonian fluid, modelled by a Herchel-Bulkley law, transported by a pressure forcing in a 2D channel with fixed walls. We observe that the rheology of the mucus and the type of signal govern a rich physics that conditions the transport of the fluid. In a second step, we analyse the same forcing and fluid conditions, but in a channel whose walls are mobile and can move according to the internal depressions of the channel as a function of a parameter qualifying the ease of wall movement. It is shown that the flow conditions as well as the transported fluid flow rate are strongly influenced by the wall flexibility parameters. 

Jury :
Directeur de these  M. Julien FAVIER  Aix Marseille Université / M2P2
Rapporteur  M. Benoit HAUT  Université libre de Bruxelles
Rapporteur  M. Benjamin MAUROY  Laboratoire J.A. Dieudonné, Université de Nice Sophia-Antipolis
Examinateur  Mme Annie VIALLAT  Aix Marseille Université / CINAM
Examinateur  M. Simon MENDEZ  Université de Montpellier / IMAG
CoDirecteur de these  M. Umberto D'ORTONA  Aix Marseille Université / M2P2
5 octobre 2022 - Improvement of heat and mass transfer predictions at solid walls in Lattice Boltzmann simulations of thermal flows / PhD defense GUANXIONG WANG
Doctorant :  Guanxiong WANG 

Date : Mercredi 5 Octobre 2022 à 14:00 / Amphi 3, Centrale Marseille

Abstract : This work is a part of the project ALBUMS (Advanced Lattice-Boltzmann Understandings for Multi-physics Simulations) which aims at promoting the Lattice Boltzmann method (LBM) to full scale realistic industrial applications. Originally designed as a weakly compressible solver, many attempts have been made during the last three decades to remove the scientific locks of major importance for the use of LBM.However, the solid wall modeling with the presence of turbulent boundary layer and the prediction of heat dominated flow still challenge its applications especially at high Reynolds number with large temperature differences. The purpose of this manuscript is to improve the LBM's robustness, accuracy and efficiency in the solid wall modeling as well as to extend its ability on predicting heat transfers in the limit of low-Mach number which constitute two main axes of this thesis. The solid wall modeling and mass leakage issues are firstly investigated.The cut-cell immersed boundary (IBM) method based on regularized boundary condition is adopted because of its outstanding advantages such as robust, easy to implement, suited to deal with complex geometries etc. All of these properties are required in engineering configurations.This boundary condition is evaluated using a classical weakly compressible LB method in an isothermal regime while the pressure-based LB method is employed to address thermal regimes. It's observed that significant mass leakage may occur at solid walls which degrades the accuracy of the solutions and the reliability of the simulations.In order to circumvent this problem, a spatial-temporal relaxation mass correction scheme is adopted for the simulation of isothermal turbulent flows. For non-isothermal flows however, there may still be significant mass leakage, and the redefined zero-order moments of the distribution function of pressure-based LB method complicates the analysis of the mass leakage issue. To solve this, a mass correction scheme is then proposed based on the compressible LB method and applied to the classical natural convection scenario.Furthermore, an advanced near wall modeling via a blending RANS/LES approach is proposed in the framework of LBM to simulate high Reynolds number turbulent flows. Regarding the prediction of heat dominated flows, which was one of the main task of this work, the pressure-based LB method suffers from the time restriction issue for low-Mach thermal flows which makes the simulations inefficient.For this reason, a new hybrid thermal LB solver based on the well-known low-Mach number approximation (LMNA) is proposed and validated on various thermal flow configurations. At least a 10 times speed-up is achieved while keeping high accuracy compared to the reference according to this study. 

Jury :
Rapporteur  M. Frédéric KUZNIK  INSA LYON / CETHIL
Rapporteur  M. Adrien TOUTANT  Université de Perpignan / PROMES
Examinateur  M. Nicolas GOURDAIN  Université Fédérale Toulouse Midi-Pyrénées / ISAE-Supaero
Examinateur  Mme Virginie DARU  ENSAM Paris
Directeur de these  M. Eric SERRE  AMU / CNRS M2P2
CoDirecteur de these  M. Pierre SAGAUT  AMU / CNRS M2P2