 Bertrand Maury
  
               Bertrand Maury   
        
                   
 
        
    
        Equipe
      ANEDP, 
        Laboratoire de
      mathématiques, Université Paris-Sud
    
        Professeur associé au DMA,
    Ecole Normale Supérieure.
        
        Membre du bureau d'AMIES
    
        Bureau 2A5, bâtiment 307
        Laboratoire de Mathématiques, Université Paris Sud
        91405 Orsay Cedex
        01 69 15 74 91    
         Bertrand.Maury @ math.u-psud.fr
    
    
    
 
    
 
      Publications
    
    
    
 
    Research interests
    
                Particulate
        flows   
           
                   
        Fluid-particle solvers
                   
        Handling of contacts
      (dry and lubricated)
    
                Modeling
      of the respiratory system
    
                Modelling
      of crowd motions           
    
                Optimization
      under constraint
            
    
 
    
    Particulate
          flows
      
    Direct simulation of fluid particle flows
    
    To simulate the motion of rigid particles in a viscous fluid, we firstly
    used the so-called  Arbitrary
      Lagrangian Eulerian approach, which relies on an unstructured mesh
    that follows the motion of the particles (see [6], 
    1999)). This method relies on an unstructured mesh which locally fits the
    boundary of the particles (click on the mesh to see an animation of a moving
    periodic mesh in the case of sedimentating particles):
    
    The mesh moves smoothly as the time goes on, until its quality gets too low,
    making it necessary to rebuild a new mesh, onto which the current velocity
    field is to be projected. We developped a Finite Element code, which handles
    biperiodic boundary conditions. This code is currently used by Julien
    Couder, at IPGP, to model sedimentation flows. It is thoroughly described in
    [6]. Note that contacts are handled in this
    approach by a very rough method, which cannot be  properly justified
    from the modelling standpoint, but which makes computations quite robust.
    See below some remarks on
    better (or, at least, more justified) ways to handle those contacts. 
    
    
    With a former PhD student, Mourad
      Ismail, we proposed and developped a completely different approach to
    handle rigid particles in a fluid domain, namely the Fat
      Boundary Method. In the spirit of the Fictitious Domain Method, as
    developped by Roland Glowinski
    , this method makes it possible to use a cartesian mesh, on which fast
    solvers can be used. Yet, the way to take the particles into account is
    quite different, as it is based on a domain decomposition approach with
    overlapping: the domain is decomposed onto a large (fictitious) domain which
    covers the mixture, and a set of narrow domains surrounding the particles.
    See  [9]  for a presentation of this method for
    the Poisson problem, and  [14] or  Mourad
      Ismail's homepage for applications to Navier-Stokes flows. It has not
    been implemented with high order Finite Element, but theoretical
    analysis  (joint work with Silvia Bertoluzza, see [14])
    suggests an optimal convergence rate, which is not common for FE
    approximation on a mesh which does not respect the boundary of the domain.
    
    
    In order to provide a simple tool to compute fluid-particle flows, we (with
    Joāo Janela and Aline
      Lefebvre, a student at Orsay) applied the penalty
      method to this type of problem. The rigid body motion is simply
    obtained by forcing the strain to be small within the bodies (penalty
    method). This approach is similar to what is done by Caltagirone's team in
    Bordeaux. Compared to the previous method, it presents the drawback to
    change the  operator which acts on the velocity: it destroys the
    well-ordered hierachical spectral structure of the Laplace operator, and
    consequently rules out the possibility to use standard fast solver for the
    global system. On the other hand, this method is quite easy to implement (it
    can be done in a few lines with the free software Freefem++
    ). An application of this method to a simple model of (rigid) cardiac valve
    is presented in [18] (2005).
    Note that, for particulate flows, contacts still need to be handled in a
    proper way. To that purpose, Aline
      Lefebvre adapted the method proposed in [20], and a
    FreeFem++ script to simulate fluid-particle flows in a robust way is now
    available. More complex  constraints can be easily added to the
    numerical model, e.g. particles which are subject to remain at a given
    distance.
    Despite its conceptual simplicity, error estimates in both h and epsilon
    (the penalty parameter) are not straightforward to obtain for this method.
    We established the expected error in h^(1/2) + epsilon  for a scalar
    version of the rigid motion constraint [29]. 
    
    Blood flows
    The techniques presented previously to simulate the motion  of rigid
    particles in a fluid can be applied to study the equivalent viscosity of
    complex mixtures like blood. As a first step, we can consider that red blood
    cell are rigid, and surrounded by a newtonian fluid (the non-newtonian
    character of the blood at a larger scale is precisely due to the presence of
    red cells). We performed some computations of collection of rigid bodies in
    a fluid submitted to a shear motion. See [22]
    (2005) for some computations (based on the ALE approach) of the effective
    viscosity of a mixture of a viscous fluid and interacting, rigid bodies.
    With S. Martin, S. Faure, and T. Takahashi, we are currently working on more
    realistic representations of the actual red blood cells. Each cell is
    modelled as an assembly of 11 spheres, submitted to spting-like
    interaction  forces to mimic their deformability. Click on the picture
    below to download an avi movie (37 Mo) representing those cells aggregating
    under the action of some interaction forces.
    
    
    
    
    
    
    
    
    Contacts
      / granular flows
      
    Initially motivated by the need to handle numerical collisions in the
    direct simulation of fluid particle flows, we developped a code to compute
    the motion of (2D or 3D) spherical grains, under the assumption of
    non-elastic shocks. Moving obstacles can be taken into account, as the
    following animations illustrate.
    
 
    

    
    This method is presented and analysed in [20]
    (2006). It is unconditionnaly stable (large time steps can be used), and can
    be shown to convergence in the case of a single contact. Note that this
    convergence is up to a subsequence, as the solution to the evolution
    equation is not unique, even if the data is regular (only analyticity
    ensures uniqueness, as showed by M.
      Schatzman). The scheme we propose is able to recover 2 different
    solutions associated to the same set of data, as detailed in [20]
    (two subequences of time steps converge to two different solution to the
    very same problem). This is somewhat anecdotical from the modelling
    standpoint, as the forcing term which leads to non-uniqueness is not likely
    to be faced in  nature, but this situation is rare enough to be
    mentioned.
    
    
    For wet grains, interaction (lubrication) forces between neighbouring
    particles can be taken into account.
    It motivated the approach presented in  [4], which
    is based on an asymptotic expansion of the normal and tangential interaction
    forces between two spheres in relative motion. This method leads to 
    badly conditionned matrices, which are difficult to handle numerically. We
    recently proposed an simplified version of this lubrication model (see [25],
    2007). This model has been extended to many-body situations by A.
      Lefebvre.
    This model is somewhat paradoxal: whereas it is designed to  handle
    interaction between rigid bodies in a highly viscous fluid (so that
    lubrication force play a significant role before actual contact, because of
    surface roughness for example, occurs), it is obtained as the vanishing
    viscosity limit of a lubrication model. This apparent contradiction is
    discussed in [25] (2007), and more thoroughly
    in Aline
      Lefebvre's PhD thesis.
    
    
    
    Coagulation fragmentation
      
    We applied granular flow techniques to the simulation of coagulation
    phenomena. The coagulation is obtained by turning on an strong attractive
    force when two particles get into contact. The method is detailed in [16] (2004).
    
    Animations to download (1.1 Mb, 1.9 Mb, and 3.9 Mb)
    
    
    


    
    Note that, if computations can be carried out with no harm,  this
    second-order evolution problem with unilateral constraints and stochastic
    forcing term does not fit into any standard class of problems. Following a
    discussion we had last december, Jean
      Bertoin established the first theoretical results concerning this type
    of problem, in the case of a single contact (see link).
    
    
    
    Crowd motion
      
    A simple model for crowd motion can be build up in the spirit of
    granular flow models with non-elastic shocks. With Juliette
      Venel, a PhD student at Orsay, we are working on the theoretical
    aspects of this model, and proposed a numerical scheme to discretize it.
    This work is ongoing. See an example of 1000 persons evacuating a square
    room with obstacles in front of the exit
    (.gif, 2.9 Mb), or, for those who are
    familiar with the RER station Gare du Nord, another example (gif,
      6Mb).  This model takes the form of a differential inclusion,
    with a difficulty due to the non convexity of the feasible set: the
    multivalued operator is not maximal monotone. It is indeed the outward
    normal cone to a set which is not convex (set of discs with non-overlapping
    constraint). But as the set is prox-regular, recent results by L.
      Thibault provide a sound theoretical framework for this model, see [24],
    a  poster
    realized for the CANUM 2006, or  [38].
    More recently 
    
    
    
    Free
          surface flows
    
    This activity dates back to the PhD I did at University Paris 6, under the
    supervision of O. Pironneau, on the flat glass forming process. I
    developped  a 3D Navier-Stokes Finite Element solver for free surface
    flows with surface tension. We introduced a new method to advect a free
    surface, which may be called projected characteristics, as an advection
    equation is solved on a plane around each point of the surface by a method
    of characteristics. This method allows to use large time steps (no CFL
    condition is required). It is presented in detail in [2].
    Another issue was raised by the surface tension forces, which are 
    proportionnal to the mean curvature. We show (see [2]
    again) that this curvature can be integrated in the standard variational
    setting. We established the convergence (order 1/2 in h, the mesh diameter)
    of this way to take into account the surface tension for a 2D problem (see [23]).
    See below a stationary state for a 2D model of the float glass forming
    process (the molten glass floats over a bath of tin).
    
    
    
    
    The next set illustrate the stability of the characteristic method to advect
    the free surface, in case of a surface velocity with a predominating
    tangential component (about 4 time steps between each snapshot).
    
    



    
    
    
    
     
    Modelling
        of the respiratory system
      
    This activity started within the  Project
        ACINIM LePoumonVousDisJe.
    Our activities concentrated on the following aspects :
    - design of suitable outlet boundary
      condition at interfaces between the upper part of the tree (where
    the flow obeys Navier-Stokes equations) and the distal part (where the air
    flow flows Stokes equations, and therefore can be described by means of
    Poiseuille-type laws). We proposed BC which we called dissipative, as they
    involve the equivalent Poiseuille relation in the downstream subtree, and
    lead to dissipative term in the variational formulation. Different forms of
    those conditions are described in [19] (2005).
    Three-dimensional experiments were performed (collaboration with C.
      Grandmont and L.
      Baffico).
    
    - coupling of the Navier-Stokes part to a spring-mass system to model the
    paremchyma:
    
    
    
    With this approach, the ventilation is caused by a force acting on the
    piston (which represents the paremchyma). This model was first introduced in
    [17] (2005).  A theoretical analysis of
    this model and some numerical test are proposed in [26]
    (2007).
    
    - Investigation of the role of the smooth
      muscle in  the ventilation process. This is a joint work
    with Sebastien Martin
    (Orsay), Thomas Similowski, and Christian Strauss (Pitié-Salpêtrière,
    Paris).  We proposed a simple respiration model process
    (ventilation + diffusion of O2 in the blood) to investigate the (possibly)
    positive role of smooth muscle contraction upon the overall efficiency of
    the respiratory process. This work has been publisshed in [29].
    
    - Coupling of a  bronchial tree (assuming Poiseuille law is verified
    for all branches) with a spring mass system (1D model for the paremchyma).
    With C.
      Grandmond and N. Meunier (see [21], 2006), we
    obtained a new constitutive equation (in the one-dimensional case)  for
    an elastic media perforated with holes containing an incompressible gas,
    which communicate through a network of pipes through which the gas flows and
    dissipates energy. It leads to a wave-like equation with a non local
    dissipative term. It is not clear whether the damping is exponential or not.
    This very point is presently investigated by C. Grandmont and C. Vannier.
    
    - Elaboration of an infinite tree
    model to describe in some way the regularity of the pressure field within
    the  paremchyma. This work, somewhat exploratory and, for the time
    being, academic, addresses the following question : the pressures at
    alveolae form a set of discrete values (1 value per alveola, about 300
    million in the human lung), uniformly distributed over the space domain
    occupied by the paremchyma. It is tempting to replace this collection of
    values by a continuum. 
    As a first step (with C. Vannier, PhD student) we had the number of
    generations of the actual tree (23 in practice) "go to infinity". We
    obtain an infinite dyadic, resistive tree T, on which a Sobolev space H^1
    can be defined (set of nodal pressures which dissipate a finite rate of
    energy). The question is now whether a trace space can be defined (the
    boundary of  T can be identified with the space  of  random
    walks in Z). We obtain a non trivial trace space (H^1/H^1_0 is not {0}) as
    soon as the global resistance if finite (which is the case for the infinite
    version of a healthy lung). The next step (in collaboration with Delphine
    Salort) consists in imbedding the infinite set of leaves (=alveolae in
    practice) onto a real domain in R^d, in order to investigate the possibility
    to identify natural functional spaces for the pressure, and describe the
    regularity of feasible pressure fields. Under suitable assumptions (regular
    tree, regular embedding of the set of ends in the domain) we establish that
    the pressure field presents some sort of  regularity in space: it
    belongs to  H^0.15 (for d = 3). 
    This work is described in [30].
     
    Unclassified
    
    Optimization under constraint
      
     With Guillaume Carlier and Thomas Lachand-Robert, we considered the
    problem which consists in projecting
    a function onto the cone of convex
      functions for the H1 norm. This problem is quite flat
    from a theoretical point of view, yet finding an effective way to
    approximate the solution to this problem is much less straightforward. 
    One of the difficulties is that the piecewise P1 interpolation of a convex
    function is itself not convex in general, which rules out the possibility to
    handle the convexity constraint in a standard, strong way (the constrained
    discretized space is "too small"). 
    A first answer to that problem was proposed by Thomas Lachand-Robert. it
    consists in working on the larger space of all those piecewise P1 functions
    which are not necessarily convex, but which interpolate a convex function.
    This relaxed constraint at the discrete level can be expressed in terms of
    values of the discrete function at the nodes of the triangulation. Note that
    most of those constraints are non local. With Guillaume Carlier, we analysed
    and implemented this method (see [10], 2001). A
    convergence result can be established for this method, but it is still too
    expensive to be applied to real life problems.
    Therefore we followed a completely different strategy, which relies on a
    dual expression of the convexity constraint. Numerical computations
    (presented in [7]) exhibits a fairly
    satisfactory behaviour, yet the numerical analysis of the approach is
    difficult because the continuous saddle-point formulation is ill posed. The
    problem takes the following abstract form: Let Ac by the cone of convex
    functions (in H1(O)).  Let B be a Hilbert space (in our case
    the set of L2 function defined over O times O ). Ac is identified
    with the reciprocal range by C of a convexe cone Bo+
    in B, which is defined as the polar cone to B+, closed convex
    cone of B (in our case the set of nonnegative functions, onto which it is
    easy to project, which is what the method relies on). Now the problem is:
    the range of C is not closed, so that neither uniqueness nor existence for
    the Lagrange multiplier is guaranteed. There are  infinitely many ways
    to bluid up C, for the convexity constraints, but none of them (at least
    among those we have considered) has the closed range property. Those
    considerations are detailed in [7] (1999).
    
    
    Full analysis of the method has not been done, but the
    fairly good behaviour of the algorithm can be explained by the following
    consideration: in the continuous version of the Uzawa algorithm (seen as a
    time-discretization of a gradient flow in the space of Lagrange
    multipliers), we established weak convergence (at least of a subsequence) of
    the primal trajectory to the solution to the minimization problem, even in
    the case the saddle-point problem is ill-posed (i.e. the Lagrange multiplier
    does not exist). The  proof is given in [12]
    (2003), and it suggests at least why the parameter in the Uzawa algorithm
    does not degenerate as h (the mesh diameter) goes to 0.
    Note that all this is related to the general study of the asymptotic
    behaviour of the solution to an homogeneous  differential inclusion
    involving a maximal monotone operator, which has been intensively studied in
    the 70's.  Yet, to our knowledge, none of the standard results include
    the case of a maximal monotone operator whose range does not contain 0
    (which is the problem we face here).
    
    
      Maximization of the first
      eigenvalue of the Laplace operator with respect to the domain
      
    With Geoffroy Billotey, student at Ecole Polytechnique, we developped
    a numerical tool, to investigate the following problem: Given N circles with
    same radius r, in a bounded domain, find the configuration which maximizes
    the smallest eigenvalue of the Laplacian with Dirichlet boundary conditions.
    After some elementary spectral analysis of the heat equation, this problem
    can be expressed from a modelling point of view: given a hot plate and a set
    of coolers, where to put them in order to optimize the cooling process? This
    work is not published. 
    The method is simply based on a gradient flow associated to  the
    smallest eigenvalue seen as a functional of the center locations.
    The following animation represents the trajectory of ten particles, which
    converges toward a (local ?) maximum of the first eigenvalue (Download
      2.4 Mb, .avi). This second animation corresponds to the same situation
    with a different initial conditions; it converges, after a short nap around
    a seemingly quasi-equilibrium point,  to  a situation symmetric to
    the previous one (Download 5.7 Mb, .avi).
    
    
 Publications
    
     
         
         [73] J.-L. Cercos-Pita, L. Fardin, H.  Leclerc, B. Maury, G. Perchiazzi, A. Bravin, S. Bayat,
         Lung Tissue Biomechanics Imaged with Synchrotron Phase Contrast Microtomography in Live Rats,
         Scientific Reports - Nature volume 12, Article number: 5056 (2022),  
         Download 
    
 
    
       [72] F. Al Reda, B. Maury, Game-Theoretic and Inhibition-Based models for crowd motion ,
      Comptes Rendus. Mathématique, Tome 359 (2021) no. 9, pp. 1071-1083.,  HAL.
    
    
    [71] F. Bourdin, B. Maury, Multibody and macroscopic impact laws: a
      Convex Analysis standpoint (2020),  HAL.
    
    [70]   H. Lavenant, B. Maury,  Opinion
        propagation on social networks : a mathematical standpoint,
      ESAIM: Proceedings and Surveys, 2020, Vol. 67, p. 285-335,  ESAIM
        Procs,     HAL
      
    [69] A. Decoene, S. Martin, B. Maury, Direct simulation of rigid
      particles in a viscoelastic fluid, in Journal of Non-Newtonian Fluid 260
      (october 2018) HAL.
    
     
    [68] B. Maury, S. Faure, J.
      Angelé, R. Bachimont, A Time -continuous Compartement Model for Building
      Evacuation, Third European Symposium on Fire Safety, Journal of Physics:
      Conference Series, Volume 1107, Evacuation (link).
    
    
    [67] B. Maury,
        S. Faure, Crowds
        in Equations,
        London: World Scientific Publishing Europe Ltd, 2018,  link
      
    [66] B.
      Grec, B. Maury, N. Meunier, and L. Navoret, A
      1D model of leukocyte adhesion coupling bond dynamics with blood velocity,
    J
          Theor Biol. 2018
        Mar 20;452:35-46.  HAL.
    
    [65] B Maury, Grains de foules, Gazette des Mathématiciens No 152, avril
    2017  HAL.
    
    [64] M. Fabre, S. Faure, M. Laurière, B. Maury, C. Perrin, Non classical
    solution of a conservation law arising in vehicular trafic, ESAIM:
      Proceedings and Surveys 55, 131-147,  HAL.
    
    [63] B. Maury, Congested
      transport at microscopic and macroscopic scales
    7th European Congress of
      Mathematics (7ECM), Jul 2016, Berlin, 
        7ECM Proceedings, 2017  HAL.
      
     [62] H. Guénard, J.-B. Martinot, S. Martin, B. Maury, S. Lalande, C.
    Kays, In vivo estimates of NO and CO conductance for haemoglobin and forlung
    transfer in humans, Respiratory Physiology & Neurobiology 228 (2016)
    1–8.
    
    [61] F. Al Reda, B. Maury, Interpretation of Finite Volume discretization
    schemes for the Fokker Planck equation as gradient flows for the discrete
    Wasserstein distance, Topological
      Optimization and Optimal Transport: In the Applied Sciences 15, 333 
    HAL
    
    [60] S. Di Marino, B. Maury, F. Santambrogio, Measure sweeping processes,
    Journal of Convex Analysis, Special Volume dedicated to the memory of Jean
    Jacques Moreau, 1923 - 2014,  Vol. 23, Nr 2 (2016)   HAL
    
    [59] B. Maury, A. Preux, Pressureless Euler equations with maximal density
    constraint : a time-splitting scheme, Topological
      Optimization and Optimal Transport: In the Applied Sciences 17, 333 
    HAL
    
    [58] S. Martin & B. Maury, Notion de résistance de l’arbre pulmonaire
    bronchique dans la ventilation respiratoire humaine,  in “Modéliser
    & simuler”, Tome 2, Matériologiques, 2014.
    
    [57] B. Maury, The resistance of the respiratory system, from top to bottom,
    Esaim Proceedings and Survey, december 2014, Vol. 47, p. 75-96  pdf
    
    [56] S. Faure, B. Maury, Crowd  motion from the granular standpoint,
    Mathematical Models and Methods in Applied Sciences Vol. 25, No. 3 (2015)
    463–493  pdf.
    
    [55]  B. Maury, non smooth
    evolution models in crowd dynamics: mathematical and numerical issues, in
    Collective Dynamics from Bacteria to Crowds, An Excursion Through Modeling,
    Analysis and Simulation, Series: CISM International Centre for Mechanical
    Sciences, Vol. 553 (2014). pdf
    
    [54]   B. Maury, A. Roudneff-Chupin, F. Santambrogio, Congestion
    driven dendritic growth, Discrete and Continuous Dynamical Systems, Volume
    34, number 4, April 2014,  preprint.
    
    [53] B. Fabrèges, B. Maury, Approximation of Single Layer Distributions by
    Dirac Masses in Finite Element Computations, Journal of Scientific
    Computing, January 2014, Volume 58, Issue 1, pp 25-40 (arXiv).
    
    [52] B. Fabrèges, L. Gouarin, B. Maury, A smooth extension method,
    Comptes Rendus Mathematique, Volume 351, Issue 9, Pages 361-366 (2013)
        pdf
       
     [51] B. Maury, The Respiratory System in Equations (MS&A), ed.
    Springer (book), 2013, link
    
    [50] S. Martin, B. Maury, Modeling of the oxygen transfer in the respiratory
    process, 
    ESAIM: Mathematical Modelling and Numerical Analysis / Volume 47 / Issue 04
    / July 2013, pp 935-960,HAL
      .
    
    [49] A. Decoene,  B. Maury,  Moving meshes with freefem++. Journal
    of Numerical Mathematics. Volume 20, Issue 3-4, pp. 195–214 (2012).
    
    [48] J. Dambrine, B. Maury, N. Meunier, A. Roudneff-Chupin,   A
    congestion model for cell migration, Communications on Pure and Applied
    Analysis 11, 1 (2012) 243-260. (arXiv)
    
    [47] Aline Lefebvre-Lepot,  Bertrand Maury, 
    Numerical Modeling of Fluid-Grain Interactions, Close Interaction of
    Immersed Grains, chapters 11 and 12 in Discrete Numerical Modeling of
    Ganular Materials, arang Radjai, Frederic Dubois Eds., ISTE Ltd and John
    Wiley & Sons Inc, march 2011 link.
    
    [46] B. Maury, Prise en  compte de la congestion dans les modèles de
    mouvements de foules, in Actes des Colloques Caen 2012-Rouen 2011, pdf.
    
     [45] Aline Lefebvre-Lepot,  Bertrand Maury, Micro-Macro Modelling
    of an Array of Spheres Interacting Through Lubrication Forces,  Adv.
    Math. Sci. Appl. 21 (2011), no. 2, 535–557,  hal
    
    [44] C. Grandmont, B. Maury, Integrated Multi-Model Description of the
    Human Lungs, in Coupled Fluid Flow in Energy, Biology and Environmental
    Research,  E-Book Series Progress in Computational Physics (PiCP),
    Volume 2, Matthias Ehrhardt (ed.), Bentham Science Publishers, Springer
    2011. pdf
      
    [43] A. Decoene, S. Martin, B. Maury, Microscopic modelling of active
    bacterial suspensions, 
    Mathematical Modelling of Natural Phenomena 2011 6 (05) : pp 98-129 (hal).
    
     [42] A. Decoene, A. Lorz, S. Martin, B. Maury, M. Tang, Simulation of
    self-propelled chemotactic bacteria in a Stokes flow, ESAIM: Proceedings,
    30, 105-124 (2010). (.pdf)
    
    [41] B. Maury, A. Roudneff-Chupin, F. Santambrogio, J. Venel,
     Handling Congestion in Crowd Motion Modeling,  Networks and
    Heterogeneous Media, Volume 6, Number 3, September 2011, pp. 485–519 (arxiv).
    
    [40] F. Bernicot, B. Maury, D. Salort,   A 2-adic approach of the
    human respiratory tree,  Netw. Heterog. Media 5 (2010), no. 3, 405–422
    (arxiv).
    
    [39] S. Bertoluzza , M. Ismail,  B. Maury,  Analysis of the fully
    discrete Fat Boundary Method, Numerische Mathematik, Volume 118, Number 1,
    49-77 (2011).
    
     [38] B. Maury, J. Venel, A discrete Contact Model for
    crowd Motion,  ESAIM: M2AN 45 1 (2011) 145-168. (hal).
    .
    [37] C. Bui, P. Frey and B. Maury, A coupling strategy based on anisotropic
    mesh adaptation for solving two-fluid flows, International Journal for
    Numerical Methods in Fluids, Volume 66, Issue 10, August 2011, Pages:
    1226–1247 (pdf).
    
    [36] B. Maury, A. Roudneff-Chupin, F. Santambrogio,  A macroscopic
    Crowd Motion Model of the gradient-flow type, Mathematical Models and
    Methods in Applied Sciences Vol. 20, No. 10 (2010) 1787-1821 (arxiv).
    
    [35] A. Devys, C. Grandmont, B. Grec, B. Maury and D.Yakoubi, Numerical
    method for the 2D simulation of the respiration, ESAIM: Proc., August 2009,
    Vol. 28, p. 162-181 (link).
    
    [34] S. Faure, S. Martin, B. Maury and T. Takahashi, Towards the simulation
    of dense suspensions: a numerical tool, ESAIM: Proc., 2009, Vol. 28, pp.
    55-79 (.pdf).
    
    [33] L. Baffico, C. Grandmont, B. Maury,  Multiscale Modelling of the
    Respiratory Tract, Math. Models Methods Appl. Sci. 20 (2010), no. 1, 59-93 (.pdf).
    
    [32]  B. Maury, D. Salort, C. Vannier,  Trace theorems for trees,
    application to the human lung, Network and Heterogeneous Media, Volume 4,
    Number 3, September 2009 pp. 469--500 (.pdf). 
    
    [31] B. Maury, J. Venel, A Mathematical Framework for a Crowd Motion Model,
     C. R. Acad. Sci. Paris, Ser. I 346 (2008) 1245--1250.
    
    [30] B. Maury, Numerical Analysis of  a Finite Element / Volume Penalty
    Method, SIAM J. Numer. Anal. Volume 47, Issue 2, pp. 1126-1148 (2009). (.pdf)
    
    [29] S. Martin, T. Similowski , C. Strauss,   B.
    Maury,  Impact of respiratory mechanics model parameter on gas exchange
    efficiency, ESAIM Proc, June 2008, Vol. 23, p. 30-47 (link).
    
    [28] V. Girault, H. Lopez, B. Maury, Energy balance of a 2-D model for
    lubricated oil transportation in a pipe, Divulgaciones Matematicas Vol. 16
    No. 1(2008), pp. 87--105 (pdf).
    
    [27bis] S. Del Pino, B. Maury, 2d/3d turbine simulations with freefem++, in
    Numerical Analysis and Scientific Computing for PDEs and their Challenging
    Applications, J. Haataja, R. Stenberg, P. Raback and P. Neitaanmäki, eds,
    CIMNE, Barcelona, Spain, 2008. (.pdf
      1Mo)
    
    [27]  C. Bui, P. Frey, B. Maury,  Methode du second membre modifié
    pour la gestion de rapports de viscosité importants dans le probleme de
    Stokes bifluide, C. R. Mecanique 336 (2008) 524--529. 
    
    [26] C. Grandmont, B. Maury, A. Soualah, Multiscale
    modelling of the respiratory track : a theoretical framework (2007),
     Proc,  June 2008, Vol. 23, p. 10-29 (.pdf).
    
    [25] B. Maury, A gluey particle model, ESAIM Proceedings,
    July 2007, Vol.18, 133-142 
    Jean-Frédéric Gerbeau & Stéphane Labbé, Editors (.pdf,
      200
      kb).
    
    [24] B. Maury, J. Venel, Un modèle de mouvements de foule
    (in french), ESAIM Proceedings, July 2007, Vol.18, 143-152,
    Jean-Frédéric Gerbeau & Stéphane Labbé, Editors (.pdf,
964
      kb).
    
    [23] V. Girault, H. Lopez, B. Maury, One time-step finite
    element discretization of the equation of motion of two-fluid flows,
    Numerical Methods for Differential Equations, vol. 22. 3, pp. 680-707, 2006
    (.pdf, 200 kb). 
    
    [22] A. Lefebvre, B. Maury,  Apparent viscosity of a
    mixture of a Newtonian fluid and interacting particles,  Fluid-solid
    interactions: modeling, simulation, bio-mechanical applications, Comptes
    Rendus Mécanique, Volume 333, issue 12, december 2005, p.p. 923-933(.pdf,
      712 kb).
    
     [21] Céline Grandmont, Bertrand Maury,  Nicolas
    Meunier, A viscoelastic model with
    non-local damping application to the human lungs, Mathematical Modelling and
    Numerical Analysis, Vol. 40 No. 1, pp 201-224, 2006 (.pdf,
      900 ko).
    
    [20] B. Maury, A time-stepping scheme for inelastic
    collisions, Numerische Mathematik, Volume 102, Number 4, pp. 649 -
    679,  2006 (.pdf, 1.4 Mo). 
    
    [19] B. Maury, N. Meunier, A. Soualah, L. Vial, Outlet
    Dissipative conditions for air flow in the bronchial tree, ESAIM
    Proceedings, september 2005, vol. 14, 115-123, Eric Cancès &
    Jean-Frédéric Gerbeau, Editors (.pdf, 800
      kb).
    
    [18] J.  Janela, A. Lefebvre, B. Maury, A penalty
    method for the simulation of fluid-rigid body interaction, ESAIM
    Proceedings, september 2005, vol. 14, 201-212, Eric Cancès &
    Jean-Frédéric Gerbeau, Editors (.pdf, 500kb).
    (N.B.  the associated source code can be downloaded NSpenal.edp).
    
    [17] C. Grandmont, Y. Maday, B. Maury, A
    multiscale/multimodel approach of the respiration tree. New trends in
    continuum mechanics, 147--157, Theta Ser. Adv. Math., 3, Theta, Bucharest,
    2005.
    
    [16] B. Maury, Direct Simulation of Aggregation Phenomena,
    Comm. Math. Sci. supplemental issue, No 1, pp. 1-11, 2004 (.pdf,
      1.1Mb).
    
    [15] B. Maury, Analyse
      Fonctionnelle, exercices et problèmes corrigés (livre), éd. Ellipses,
    2004. Description (en français).
    
    [14] S. Bertoluzza, M. Ismail, B. Maury, The FBM Method:
    Semi-Discrete Scheme and Some Numerical experiments. Lecture Notes in Comp.
    Sc. and Eng.,  2004 (.pdf, 530 kb).
    
    [13] B. Maury,  Fluid-particle shear flows, ESAIM M2AN., 37,  No
    4, pp. 699-708,  2003 (.pdf,
      1.2Mb). 
    
    [12] B. Maury, Version continue de l'algorithme d'Uzawa, C.
    R. Acad. Sci. Paris,  Série I, 337,  pp. 31-36, 2003 (.pdf,
      120 kb).
    
    [11] M. Ismail, B. Maury,  Méthode  de la frontière élargie pour
    la simulation d'écoulements fluides, Proc. du 35ème Congrès Nat. d'Ana.
    Num., La Grande Motte, pp.1-25, 2003 (.pdf, 1.6
      Mb).
    
    [10] G. Carlier, T. Lachand-Robert, B. Maury, A numerical
    approach to variational problems subject to convexity constraints, Num.
    Math.  88, pp. 299-318, 2001 (.pdf, 560Kb).
    
    [9] B. Maury,  A Fat Boundary Method for the Poisson
    Equation in a Domain with Holes, J. of Sci. Computing, 16 (2001), no. 3, pp.
    319-339 (.pdf, 700kb).
    
    [8] E. Lagarde, B. Auvert, B. Ferry, B. Maury, Concurrent partnerships and
    HIV epidemic in five urbancommunities of sub-Saharan Africa,  AIDS
    2001, vol 15, No X.
    
    [7] G. Carlier, T. Lachand-Robert, B. Maury, H1-projection
    into the set of convex functions: a saddle-point formulation, CEMRACS 1999
    (Orsay), 277-289, ESAIM Proc., 10, Soc. Math. Appl. Indust., Paris, 1999 (.ps,
      1.5 Mb).
    
    [6] B. Maury, Direct Simulations of 2D Fluid-Particle Flows
    in Biperiodic Domains, Journal of Computational Physics 156, 325-351, 1999 (.pdf,
      3.3 Mb).
    
    [5] Y. Maday, B. Maury, P. Métier,  Interaction de fluides potentiels
    avec une membrane élastique, CEMRACS 1999 (Orsay), 23-33,  ESAIM Proc.,
    10, Soc. Math. Appl. Indust., Paris, 1999 (.pdf).
    
    [4] B.  Maury, A Many-Body Lubrication Model, 
      C. R. Acad. Sci. Paris, t. 325, Série I, pp. 1053-1058, 1997 (.pdf,
      1.6 Mb).
    
    [3] B. Maury, R. Glowinski,  Fluid-Particle Flow: a Symmetric
    Formulation, C. R. Acad. Sci. Paris, t. 324, Série I, pp. 1079-1084, 1997.
    
    [2bis] B. Maury,  O. Pironneau ,  Characteristics ALE method for
    unsteady free surface flows with surface tension, Z. angew. Math. Mech.,
    ICIAM / GAMM 95. Part II, Hamburg , Allemagne, 1996, vol. 76 (4 ref.), pp.
    613-614.
    
    [2] B. Maury, Characteristics ALE Method for the 3D
    Navier-Stokes Equations with a Free Surface, Int. Journal of Comp. Fluid
    Dyn. 6, 175-188 (1996) (.pdf, 1Mb).
    
      [1] K. Boukir, B. Maury, B. Nitrosso, A characteristics-ALE
    method for variable domain Navier-Stokes equations. Computational Modelling
    of Free and Moving Boundary Problems III,  Modelling and Simulation
    volume 13, Transactions of the Wessex Institute, 1995.
    
    
 
    
 
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