Multidisciplinary Aerospace System Design: Principles, Issues and Onera Experience

With the increasing complexity of aerospace systems, it has become more and more necessary to adopt a global, integrated approach from the very early steps and throughout the design process. Tightly coupling aerodynamics, propulsion, structure, trajectory, guidance and navigation, while also taking into account environmental and societal constraints, as well as manufacturability, reliability and maintainability, is a huge challenge. The field of Multidisciplinary Design Optimization (MDO) provides some answers on how to integrate increasing knowledge into the design process, while reducing the design cycles. It consists in a core of key methodologies, such as multi-disciplinary problem formulation and decomposition, optimization under uncertainties and surrogate based high-fidelity tool integration, which are validated and enriched through confrontation with various kinds of design studies. The aim of this paper is, on the one hand, to give a clear view of the challenges at stake and the key difficulties that must be overcome and, on the other hand, to focus on some significant studies and achievements at Onera over the past decade, either on tools and methods, or on dedicated applications, illustrating the progress made and the challenges to come.