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Inégalités de Carleman globales pour les problèmes elliptiques non homogènes

Jean-Pierre Puel

Séminaire Équations aux dérivées partielles

On établit ici, suivant [5], une inégalité de Carleman globale optimale pour les solutions faibles (au sens H 1 ) d’équations elliptiques générales avec second membre dans H - 1 et trace non nulle. La motivation, qui est expliquée dans l’introduction, réside dans l’obtention d’inégalités de Carleman globale pour l’opérateur de Navier-Stokes linéarisé afin, notamment, d’étudier les questions de contrôlabilité exacte sur les trajectoires pour les équations de Navier-Stokes. Une étape majeure...

Unique continuation property near a corner and its fluid-structure controllability consequences

Axel OssesJean-Pierre Puel — 2009

ESAIM: Control, Optimisation and Calculus of Variations

We study a non standard unique continuation property for the biharmonic spectral problem Δ 2 w = - λ Δ w in a 2D corner with homogeneous Dirichlet boundary conditions and a supplementary third order boundary condition on one side of the corner. We prove that if the corner has an angle 0 < θ 0 < 2 π , θ 0 π and θ 0 3 π / 2 , a unique continuation property holds. Approximate controllability of a 2-D linear fluid-structure problem follows from this property, with a control acting on the elastic side of a corner in a domain containing a Stokes...

Approximate controllability for a linear model of fluid structure interaction

Axel OssesJean-Pierre Puel — 2010

ESAIM: Control, Optimisation and Calculus of Variations

We consider a linear model of interaction between a viscous incompressible fluid and a thin elastic structure located on a part of the fluid domain boundary, the other part being rigid. After having given an existence and uniqueness result for the direct problem, we study the question of approximate controllability for this system when the control acts as a normal force applied to the structure. The case of an analytic boundary has been studied by Lions and Zuazua in [9] where, in particular,...

Unique continuation property near a corner and its fluid-structure controllability consequences

Axel OssesJean-Pierre Puel — 2008

ESAIM: Control, Optimisation and Calculus of Variations

We study a non standard unique continuation property for the biharmonic spectral problem Δ 2 w = - λ Δ w in a 2D corner with homogeneous Dirichlet boundary conditions and a supplementary third order boundary condition on one side of the corner. We prove that if the corner has an angle 0 < θ 0 < 2 π , θ 0 π and θ 0 3 π / 2 , a unique continuation property holds. Approximate controllability of a 2-D linear fluid-structure problem follows from this property, with a control acting on the elastic side of a corner in a domain containing...

A null controllability data assimilation methodology applied to a large scale ocean circulation model

Galina C. GarcíaAxel OssesJean Pierre Puel — 2011

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

Data assimilation refers to any methodology that uses partial observational data and the dynamics of a system for estimating the model state or its parameters. We consider here a non classical approach to data assimilation based in null controllability introduced in [Puel, 335 (2002) 161–166] and [Puel, 48 (2009) 1089–1111] and we apply it to oceanography. More precisely, we are interested in developing this methodology to recover the unknown final state value (state value at the end of the measurement...

A null controllability data assimilation methodology applied to a large scale ocean circulation model

Galina C. GarcíaAxel OssesJean Pierre Puel — 2011

ESAIM: Mathematical Modelling and Numerical Analysis

Data assimilation refers to any methodology that uses partial observational data and the dynamics of a system for estimating the model state or its parameters. We consider here a non classical approach to data assimilation based in null controllability introduced in [Puel, (2002) 161–166] and [Puel, (2009) 1089–1111] and we apply it to oceanography. More precisely, we are interested in developing this methodology to recover the unknown final state value (state...

Exact controllability to the trajectories of the heat equation with Fourier boundary conditions: the semilinear case

Enrique Fernández-CaraManuel González-BurgosSergio GuerreroJean-Pierre Puel — 2006

ESAIM: Control, Optimisation and Calculus of Variations

This paper is concerned with the global exact controllability of the semilinear heat equation (with nonlinear terms involving the state and the gradient) completed with boundary conditions of the form y n + f ( y ) = 0 . We consider distributed controls, with support in a small set. The null controllability of similar linear systems has been analyzed in a previous first part of this work. In this second part we show that, when the nonlinear terms are locally Lipschitz-continuous and slightly superlinear, one...

Null controllability of the heat equation with boundary Fourier conditions: the linear case

Enrique Fernández-CaraManuel González-BurgosSergio GuerreroJean-Pierre Puel — 2006

ESAIM: Control, Optimisation and Calculus of Variations

In this paper, we prove the global null controllability of the linear heat equation completed with linear Fourier boundary conditions of the form y n + β y = 0 . We consider distributed controls with support in a small set and nonregular coefficients β = β ( x , t ) . For the proof of null controllability, a crucial tool will be a new Carleman estimate for the weak solutions of the classical heat equation with nonhomogeneous Neumann boundary conditions.

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