CERFACS CERFACS Scientific Activity Report Jan. 2010 – Dec. 2011

1 Overview presentation
The main expertise of the Electromagnetic and acoustic team concerns the numerical solution of problems
related to the wave propagations. We study the scattering of time-harmonic electromagnetic and acoustic
waves. But the transient regime in the case of electromagnetic and elastodynamic waves propagation is also
analyzed.
In 3D electromagnetism, our efforts are focused essentially on integral equations method. First we have
developed well-conditioned and accurate integral equation methods, which are implemented in the CESC
code (CERFACS Electromagnetism Solver Code) . This work is done in collaboration with ONERA.
And this activity is part of a ANR project ARTHEMIS (in partnership with ONERA and Polytechnique).
Secondly, specific attention is led to the multipole algorithm in the case of low frequency or when the mesh
is very refined.
A more recent activity concerns the numerical simulation of acoustic scattering in presence of an arbitrary
mean flow : the method couples continuous and discontinuous finite elements with Perfectly Matched
Layers. Two different approaches have been constructed and implemented. Several boundary conditions
are analyzed. This activity is part of the ANR project AEROSON (in partnership with EADS and with
POEMS and LAUM laboratories).
Our team has also produced, in collaboration with the INRIA Project DEFI, some contributions in the
domain of electromagnetic imaging by the Linear Sampling Method (LSM). In partnership with the
CERFACS Algo team, a very fast solution algorithm has been developed and tested. Some theoretical
aspects are currently studied, which could help to image the interior of the scatterer.
Finally, the team contributes to the development of a high order Discontinuous Galerkin scheme for transient
Maxwell’s equations, including local time-stepping and adaptative refinement strategy. This approach is
implemented in the ONERA code.
CERFACS ACTIVITY REPORT 47