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Julien Lequeurre

Email: julien.lequeurre@univ-lorraine.fr
Office: 218
Phone: +33 (0)3 87 54 72 89
Mail:
Institut Élie Cartan (Mathématiques)
Université de Lorraine, Site de Metz
Bât. A, Ile du Saulcy, F-57045 Metz Cedex 1


Curriculum Vitæ

Here is my detailled vitae (in french, march 2013). In a nutshell:

Maître de Conférences (Assistant professor) in IECL (in Metz, France) since september 2013.

I was a post-doctoral fellow at IECL (in Nancy, France) from September 2012 to August 2013. I began to work with Marius Tucsnak and Takéo Takahashi from the PDE team on fluid-structure interaction problems.

I was a PhD student from September 2008 to December 2011 in the Institut de Mathématiques de Toulouse (IMT) under the supervision of Jean-Pierre Raymond (IMT). I defended my Thesis on December 5th 2011.

I was a Moniteur (Teacher up to 64 hours a year) from September 2008 to August 2011, then part-time A.T.E.R. (Teacher up to 96 hours a year) from September 2011 to August 2012, both in Université Paul Sabatier, Toulouse.


Research Interests

I study fluid-structure interaction problems.

In particular, I look for the existence of strong solutions for this kind of systems. My current results (see the Publications section below) show the local in time existence of strong solutions for arbitrary large initial data and the existence on a time interval [0,T] (for T>0 fixed) of strong solutions for small initial data.

I study the controllability and the stabilisation of such fluid-structure systems. These problems have applications in aeronautics and rheology for instance.


Publications

  1. Existence of Strong Solutions to a Fluid-Structure System, SIAM J. of Mathematical Analysis, 43 (2010), No 1, pp. 389-410, doi:10.1137/10078983X.

    Abstract: We study a coupled fluid-structure system. The structure corresponds to a part of the boundary of a domain containing an incompressible viscous fluid. The structure displacement is modeled by a damped beam equation. We prove the existence of strong solutions to our system for small data and the existence of local strong solutions for any initial data.

  2. Null Controllability of a Fluid-Structure System, accepted in SIAM Journal on Control and Optimization.

    Abstract: We study a coupled fluid-structure system. The structure corresponds to a part of the boundary of a domain containing an incompressible viscous fluid. The structure displacement is modeled by an ordinary differential equation. We prove the local null controllability of the system when the control acts on a fixed subset of the fluid domain.

  3. Existence of strong solutions for a system coupling the Navier Stokes equations and a damped wave equation, in Journal of Mathematical Fluid Mechanics. This paper has only (currently) a "Online first" version which can be found on the Springer website here.

    Abstract: We consider a fluid - structure interaction problem coupling the Navier-Stokes equations with a damped wave equation which describes the displacement of a part of the boundary of the fluid domain. The system is considered first in the two dimensional setting and in a second part it is adapted to the three dimensional setting.

My thesis (in english, the introduction excepted): Quelques résultats d'existence, de contrôlabilité et de stabilisation pour des systèmes couplés fluide - structure.