Un problème aux limites pour l'équation de Korteweg-de Vries sur un intervalle borné
Modèles stratifiés en mécanique des fluides géophysiques
A multi-D model for Raman amplification
In this paper, we continue the study of the Raman amplification in plasmas that we initiated in [Colin and Colin, 17 (2004) 297–330; Colin and Colin, 193 (2006) 535–562]. We point out that the Raman instability gives rise to three components. The first one is collinear to the incident laser pulse and counter propagates. In 2-D, the two other ones make a non-zero angle with the initial pulse and propagate forward. Furthermore they are symmetric with respect to the direction of propagation of the...
A multi-D model for Raman amplification
In this paper, we continue the study of the Raman amplification in plasmas that we initiated in [Colin and Colin, (2004) 297–330; Colin and Colin, (2006) 535–562]. We point out that the Raman instability gives rise to three components. The first one is collinear to the incident laser pulse and counter propagates. In 2-D, the two other ones make a non-zero angle with the initial pulse and propagate forward. Furthermore they are symmetric with respect to the direction...
Rigorous derivation of Korteweg-de Vries-type systems from a general class of nonlinear hyperbolic systems
On the ground states of vector nonlinear Schrödinger equations
Nonlinear models for laser-plasma interaction
In this paper, we present a nonlinear model for laser-plasma interaction describing the Raman amplification. This system is a quasilinear coupling of several Zakharov systems. We handle the Cauchy problem and we give some well-posedness and ill-posedness result for some subsystems.
Rigorous derivation of Korteweg-de Vries-type systems from a general class of nonlinear hyperbolic systems
In this paper, we study the long wave approximation for quasilinear symmetric hyperbolic systems. Using the technics developed by Joly-Métivier-Rauch for nonlinear geometrical optics, we prove that under suitable assumptions the long wave limit is described by KdV-type systems. The error estimate if the system is coupled appears to be better. We apply formally our technics to Euler equations with free surface and Euler-Poisson systems. This leads to new systems of KdV-type.
Forewords
Amortissement Landau en physique des plasmas
Le but de cet article est de donner un sens au modèle mathématique décrivant l’amortissement Landau des ondes Langmuir en Physique des plasmas. L’originalité de ce modèle est la présence d’un couplage nonlinéaire entre le champ électrique, fonction de la position spatiale, et la distribution électronique des électrons en fonction de la fréquence. Ce couplage spatio-fréquentiel ainsi que les termes nonlinéaires obligent à considérer le problème simultanément en variable spatiale et fréquentielle...
Dynamics of shock waves in elastic-plastic solids
The Maxwell type elastic-plastic solids are characterized by decaying the absolute values of the principal components of the deviatoric part of the stress tensor during the plastic relaxation step. We propose a mathematical formulation of such a model which is compatible with the von Mises criterion of plasticity. Numerical examples show the ability of the model to deal with complex physical phenomena.
The role of Mechanics in Tumor growth : Modelling and Simulation
A number of biological phenomena are interlaced with classical mechanics. In this review are illustrated two examples from tumor growth, namely the formation of primordial networks of vessels (vasculogenesis) and the avascular phase of solid tumors. In both cases the formalism of continuum mechanics, accompanied by accurate numerical simulations, are able to shed light on biological controversies. The converse is also true: non-standard mechanical problems suggest new challenging mathematical questions....
3D monolithic finite element approach for aero-thermics processes in industrial furnaces ⋆
We consider in this paper a mathematical and numerical model to design an industrial software solution able to handle real complex furnaces configurations in terms of geometries, atmospheres, parts positioning, heat generators and physical thermal phenomena. A three dimensional algorithm based on stabilized finite element methods (SFEM) for solving the momentum, energy, turbulence and radiation equations is presented. An immersed volume method (IVM) for thermal coupling of fluids and solids is introduced...
Implementation of optimal Galerkin and Collocation approximations of PDEs with Random Coefficients ⋆ ⋆⋆
In this work we first focus on the Stochastic Galerkin approximation of the solution
Multiscale expansion and numerical approximation for surface defects ⋆
This paper is a survey of articles [5, 6, 8, 9, 13, 17, 18]. We are interested in the influence of small geometrical perturbations on the solution of elliptic problems. The cases of a single inclusion or several well-separated inclusions have been deeply studied. We recall here techniques to construct an asymptotic expansion. Then we consider moderately close inclusions, i.e. the distance between the inclusions tends to zero more slowly than their characteristic size. We provide a complete asymptotic...
Page 1