Overlapping method for EMC applications applied to aperture models in domain decomposition method

One of the most important problems in ElectroMagnetic Compatibility (EMC) for aeronautic projects concerns equipments vulnerability, typically electronic sheets inside cavities like avionic compartments. The objective of the simulation consists in predicting the field level inside the structure with a good accuracy, because the shielding always have predictable defects (doors and windows) or unpredictable defects (gaskets, bad boundings, ...). The field penetrates inside the structure and leads to disturbance signals at the equipment inputs and our aim is to reduce them. The work described in this paper consists in evaluating the influence of apertures since the design stage. Then numerical methods offers many possibilities in spite of their intrinsic limitations. For our problematic, we are interested in an experimental configuration composed by three cavities B, B2 and B3, with some wires inside and having dimensions of Lχx Pυ x Hζ = 100cm x 90cm x 70cm each one. The volumes are coupled by circular apertures of 5cm of diameter, whose center is 10cm above the z = 0 plane, in the symetry plane of the boxes at y = 45cm (see Fig. 3 left). We have chosen to focus on specific models for aperture coupling [9], to get an efficient method, both as to the numerical cost (memory stack, computation time) and as to the precision (dispersion error, power dissipation), for future applications to very "expensive" cases (aircraft, satellite, ...).