Soutenance de thèse : Gabriel DE CARVALHO FERREIRA SILVA

Methodology for the robust design of air bleed systems in aeronautics

Doctorant : Gabriel DE CARVALHO FERREIRA SILVA

Laboratoire INSA : AMPERE

École doctorale : ED160 : EEA (Electronique, Electrotechnique, Automatique)

At the design stage, product engineers try to find the perfect balance between the physical parameters of the components and the performance required to properly design a system. It is therefore very important to understand how the choice of physical parameters at the design stage will impact the dynamic behavior of the final product. The problem requires skills in modeling complex multi-physics systems and control theory.
This work investigates the air bleed system of aircraft in collaboration with Liebherr Aerospace Toulouse. Although the structure of each valve and the arrangement of valves in the air bleed system are well known, the parameters that critically impact performance are difficult to identify. Due to the complexity of the model required to reproduce the behavior of valves, its non-linearity and the high degree of coupling between parameters, existing tools quickly show their limits. That is why the aim of the work presented in this thesis is to propose a new methodology that closely address the dynamic aspects of these valves from the design stage and provide a relevant evaluation of their dynamic performance in relation with the design requirements. This new methodology is presented and described from its theoretical concepts to its application to practical problems; it is based on a specific modeling step followed by a numerically solved stability condition, which is formulated as a constrained optimization based on linear matrix inequalities (LMI). The main originality of this work is based on the use of optimization tools to find, not an optimal parameter value, but the admissible ranges for a set of parameters which guarantee the required dynamic behavior.