Publications

2014

• Wind turbine noise modeling: prediction of amplitude modulation and influence of atmospheric conditions
  
  • Tian Yuan
  • Cotté Benjamin
  • Chaigne Antoine
  , 2014. Aeroacoustic noise from a wind turbine is mainly caused by the interaction between the wind turbine blade and the air flow. For a modern wind turbine, trailing edge noise is often the dominant noise source. In this paper, a detailed study of trailing edge noise is carried out using Amiet's frequency domain analytical source model. Model results are compared with experimental data. Features of wind turbine noise, such as amplitude modulation, ground directivity, influence of blade twist and pitch are studied. In the last part, the influence of realistic wind profiles is investigated. Wind shear is seen to increase the sound power level and the amplitude modulation.
• Numerical experiments using a HLLC-type scheme with ALE formulation for compressible two-phase flows five-equation models with phase transition
  
  • Daude Frédéric
  • Galon Pascal
  Computers and Fluids, Elsevier, 2014. Computation of compressible two-phase flows with single-pressure single-velocity two-phase models in conjunction with the moving grid approach is discussed in this paper. A HLLC-type scheme is presented and implemented in the context of Arbitrary Lagrangian–Eulerian formulation for solving the five-equation models. In addition, the extension to multicomponent cases is also examined. The method is first assessed on a variety of Riemann problems including both fixed and moving grids applications showing its simplicity and robustness. The method is also tested on 2-D moving mesh applications including fluid–structure interactions. The heat and mass transfer modeling is finally examined for two-phase mixtures. Computations using a fractional step approach of water hammer and fast depressurization with flashing are performed. Good agreement is obtained with available experimental data. All computations are performed with the Europlexus fast transient dynamics software. (10.1016/j.compfluid.2014.02.008)
  DOI : 10.1016/j.compfluid.2014.02.008
• Numerical simulation of the fluid–structure interaction in a tube array under cross flow at moderate and high Reynolds number
  
  • Shinde V.
  • Marcel T.
  • Hoarau Y.
  • Deloze T.
  • Harran Gilles
  • Baj F.
  • Cardolaccia J.
  • Magnaud J.P. P
  • Longatte E.
  • Braza Marianna
  Journal of Fluids and Structures, Elsevier, 2014, 47, pp.99-113. The unsteady loads in a tube bundle are studied at moderate and high Reynolds number by means of URANS and hybrid (DDES) modelling. The onset of fluid-elastic instability is analysed for different structural parameters, Scruton number and reduced velocity. The simulations have been carried out with the code NSMB (Navier-Stokes Multi Block) by using turbulence modelling methods URANS and DDES (Delayed Detached Eddy Simulation). The CEA-DIVA configuration is considered for the cylinders array for an inter-tube Reynolds number 60 000. The study is carried out for a configuration of (4 Â 5) cylinders in static conditions as well as for the vertical free motion of one of the central cylinders in one DOF (Degree Of Freedom).The inter-tube Reynolds number is 60 000. It is found that this cylinder spontaneously displays an oscillatory motion which first corresponds to Vortex Induced Vibration (VIV), associated to a lock-in mechanism for low values of the reduced velocity and secondly develops Movement Induced Vibration, MIV, for higher values of the reduced velocity. The variation of the cylinder's oscillations frequency, of the unsteady loads and the structure's displacement are studied as a function of the reduced velocity for low and high values of the Scruton number. The increase of the phase-lag between the forces and the displacement is predicted and discussed for different Scruton number values and reduced velocities. (10.1016/j.jfluidstructs.2014.02.013)
  DOI : 10.1016/j.jfluidstructs.2014.02.013
• Effets météorologiques sur le bruit rayonné par les éoliennes
  
  • Cotté Benjamin
  • Tian Yuan
  • Chaigne Antoine
  , 2014. Cette étude vise à expliquer les différences observées entre le bruit rayonné par une éolienne en champ proche et en champ lointain, en montrant l'influence des conditions météorologiques à la fois sur les sources de bruit d'une éolienne et sur la propagation de ce bruit dans l'atmosphère. Des données expérimentales ont été analysées afin d'obtenir des profils de vent et de température réalistes dans l'atmosphère. Dans certains cas, les profils de vent prédits par la théorie de la similitude différent fortement des profils mesurés, ce qui conduit à des prédictions erronées du bruit rayonné en champ proche (100m) comme en champ lointain (jusqu'à 1km). Le modèle de source montre que les plus fortes amplitudes de modulation sont obtenues dans la direction perpendiculaire au vent, alors que le modèle de propagation met en évidence des niveaux sonores plus importants dans la direction du vent pour des distances supérieures à 800mètres environ.
• Some applications of a two-fluid model
  
  • Crouzet Fabien
  • Daude Frédéric
  • Galon Pascal
  • Hérard Jean-Marc
  • Hurisse Olivier
  • Liu Yujie
  , 2014, 78, pp.837-846. We present in this paper some comparisons of numerical results and experimental data in some two-phase flows involving rather high pressure ratios. A two-fluid two-phase flow model has been used herein, but we also report a few results obtained with some simpler single-fluid two-phase flow models. (10.1007/978-3-319-05591-6_84)
  DOI : 10.1007/978-3-319-05591-6_84
• Modeling long-term creep rupture by debonding in unidirectional fibre-reinforced composites
  
  • Nedjar Boumediene
  International Journal of Solids and Structures, Elsevier, 2014, 51, pp.1962-1969. Delayed fracture due to debonding can be observed in many unidirectional fibre-reinforced composites when the fibre/matrix interface experiences creep. The aim of this work is to describe such a phenomenon within the recently proposed modeling framework of transverse isotropy that allows for a neat decomposition of the mechanical behavior into fibre-directional, transverse, and pure shear parts. Specifically, debonding is here chosen to be governed by the tension transverse to the fibres. One can then speak of a mode-I debonding if use is made of the terminology adopted in fracture mechanics. On another hand, the time-dependent response is attributed to the matrix constituent. As the role of this latter is to deform and support stresses primarily in shear, a viscoelastic behavior is introduced that affects solely the pure shear part of the behavior. We show that both characteristics can be easily embedded into the aforementioned formulation. Among others, the occurrence of tertiary creep is made possible to predict. It is otherwise found that the predicted debonding path always propagates along the direction of the fibres in agreement with many experimental observations found in the literature. On the numerical side, the algorithmic treatment of debonding is independent of the one for viscoelasticity. This renders the implementation within the context of the finite element method very easy. (10.1016/j.ijsolstr.2014.02.005)
  DOI : 10.1016/j.ijsolstr.2014.02.005
• A three-dimensional analysis of fatigue crack paths in thin metallic sheets
  
  • Esnault Jean-Baptiste
  • Doquet Véronique
  • Massin Patrick
  International Journal of Fatigue, Elsevier, 2014, 62, pp.119-132. Fatigue crack growth in thin sheets of 7075 T651 aluminium alloy and S355 steel were characterised in 3D, using crack front markings and topographic reconstructions of fracture surfaces. Tests performed in air or in salt water produced different crack paths for similar mechanical condit ions, shear lips being reduced by corrosive environment, in the aluminium alloy as well as in the steel. Before the onset of shear lips development, tunnelling crack fronts were observed, due to the difference in closure effects at mid-thickness and near free surfaces. Tunnelling was progressively reduced and cancelled as slanted crack growth developed, even though DK I was reduced locally by crack twisting. This indicates a significant contribution of shear modes to the crack driving force, even though mode I striations are present in slanted zones. Elastic three-dimensional X-FEM computations were performed to analyse the observed crack growth kinetics, based on ΔKI , ΔKII and ΔKIII. The crack growth rates correlated much better to ΔKeq = √(ΔKI^2 + ΔKII^2 + (ΔKIII^2/(1-ν))) than to ΔKI. Elastic–plastic finite element simulations and the local application of a fatigue criterion with an amplitude-dependent critical plane were found to capture qualitatively the transition in fracture mode and its inhibition by side grooves. (10.1016/j.ijfatigue.2013.03.015)
  DOI : 10.1016/j.ijfatigue.2013.03.015
• Innovative tests for characterizing mixed-mode concrete fracture
  
  • Carpiuc Andreea
  • Poncelet M.
  • Kazymyrenko K.
  • Leclerc Hugo
  • Hild François
  , 2014. no abstract
• Comparison between continuous and localized methods to evaluate the flow rate through containment concrete structures
  
  • Jason Ludovic
  • Masson Benoit
  Nuclear Engineering and Design, Elsevier, 2014, 277, pp.146-153. In this contribution, different techniques are compared to evaluate the gas flow rate through a representative section of a reinforced and prestressed concrete containment structure. A continuous approach is first applied which is based on the evaluation of the gas permeability as a function of the damage variable. The calculations show that the flow rate becomes significant only when the damage variable crosses the section. But in this situation, the continuous approach is no longer fully valid. That is why localized approaches, based on a fine description of the crack openings, are then investigated. A comparison between classical simplified laws (Poiseuille flow) and a more refined model which takes into account the evolution of the crack opening in the depth of the section enables to define the validity domain of the simplified laws and especially the definition of the associated “reference opening”. (10.1016/j.nucengdes.2014.06.010)
  DOI : 10.1016/j.nucengdes.2014.06.010
• Drawing with a crack in concrete": A hybrid test to control mixed-mode crack propagation
  
  • Carpiuc Andreea
  • Poncelet M.
  • Kazymyrenko K.
  • Leclerc Hugo
  • Hild François
  , 2014. no abstract
• Stability of bubbly liquids and its connection to the process of cavitation inception
  
  • Fuster Daniel
  • Pham Kim
  • Zaleski Stéphane
  Physics of Fluids, American Institute of Physics, 2014. (10.1063/1.4870820)
  DOI : 10.1063/1.4870820
• An energetic formulation of a one-dimensional model of superelastic SMA
  
  • Pham Kim
  Continuum Mechanics and Thermodynamics, Springer Verlag, 2014. (10.1007/s00161-014-0346-9)
  DOI : 10.1007/s00161-014-0346-9