" Soutenance de thèse de Marina LISNYAK le 20 avril 09h30, Amphi Turing | Université d'Orléans

Université d'Orléans

Soutenance de thèse de Marina LISNYAK le 20 avril 09h30, Amphi Turing

20/04/2018 - 09:30 - 20/04/2018 - 12:00

Lieu: Amphithéâtre Turing - Polytech’Orléans – site Galilée - 14 rue d’Issoudun - campus UNIVERSITÉ

THEORETICAL, NUMERICAL AND EXPERIMENTAL STUDY OF DC AND AC ELECTRIC ARCS. Modélisation et expérimentation d’arcs de défaut se propageant sur des barres de distribution électrique dédiées aux applications aéronautiques.

Discipline : Physique des gaz et des plasmas

ECOLE DOCTORALE EMSTU

Résumé :

The ignition of an electric arc in the electric distribution system of an aircraft can be a serious problem for flight safety. The amount of information on this topic is limited, however. Therefore, the aim of this work is to investigate the electric arc behavior by means of experiment and numerical simulations. The MHD model of the LTE arc column was used and resolved numerically using the commercial software comsol Multiphysicsr. In order to describe plasma-electrode interaction, the model had to be extended to include non-equilibrium effects near the electrodes. These zones were taken into account by means of current and energy conservation in the non-equilibrium layer. The correct matching conditions were developed and are described in the work. Validation of the model in the case of a free burning arc showed excellent agreement between comprehensive models and the experiment. This model was then extended to the case of the electric arc between rail electrodes in a 3D geometry. Due to electromagnetic forces the electric arc displaces along the electrodes. A self-consistent description of this phenomenon was established. The calculation was performed for DC, pulsed and AC current conditions at atmospheric and lower pressures. The main characteristics of the arc were analyzed and discussed. The results obtained were compared with the experimental measurements and showed good agreement. The model of electric arcs between busbar electrodes is able to predict the behavior of a fault arc in aeronautical conditions. Further improvements of the model are discussed as an outlook of the research.