Design conceptuel d'un avion "Blended Wing Body" de 200 passagers

RESUME Le Blended Wing Body (BWB) est base sur le concept d’aile volante et presente des performances ameliorees compare a des avions conventionnels. Par contre, la plupart des etudes se sont penchees sur des avions de grande a tres grande capacite et il n’est pas clair si les gains seront les memes pour des avions plus petits. L’objectif principal de ce memoire est d’effectuer la conception conceptuelle d’un avion de type BWB de 200 passagers et de comparer les performances obtenues a un avion classique l’A320 equivalent en termes de nombres de passagers et distance franchissable. L’environnement CEASIOM a ete choisi pour realiser la conception du BWB. Cette plateforme de design connue pour le design d’avion conventionnel a ete modifiee et des outils complementaires ont ete integres afin de realiser l’analyse aerodynamique, performance et stabilite de l’avion a fuselage integre. Un modele d’avion est obtenu dans le module geometrique AcBuilder de CEASIOM a partir des variables de design d’une aile conventionnelle. Les estimations de masse sont realisees a partir de formules semi-empiriques adaptees a la geometrie du BWB et les calculs de centrage et inerties sont obtenues par un modele BWB developpe sous CATIA. Des methodes basses fidelite, comme TORNADO, et des formules semi-empiriques sont utilisees pour analyser l’aerodynamique, la performance et la stabilite de l’avion. Les resultats aerodynamiques sont valides a l’aide d’une analyse haute-fidelite utilisant le logiciel CFD FLUENT. Un processus d’optimisation est implemente afin d’obtenir des performances ameliorees tout en respectant les contraintes. Il s’agit d’une optimisation de la forme en plan de l’avion. Les performances de l’avion BWB optimise sont comparees a un A320 egalement optimise. Des gains significatifs sont observes. Enfin, une analyse de la dynamique de vol longitudinal et lateral est realisee sur l’avion BWB optimise. Cette etude a permis d’identifier les modes stables de l’avion et a mis en evidence les problemes potentiels de stabilite lies a l’oscillation d’incidence et au roulis hollandais.----------ABSTRACT The Blended Wing Body is built based on the flying wing concept and performance improvements compared to conventional aircraft. The design methodology of this type of aircraft looks different from a conventional aircraft by its unconventional shape and strong integration between different disciplines. A multidisciplinary design method was considered. The design of the Blended Wing Body was carried out under the CEASIOM environment. This platform design suitable for conventional aircraft design has been modified and additional tools have been integrated in order to achieve the aerodynamic analysis, performance and stability of the aircraft fuselage built. A plane model is obtained in the geometric module AcBuilder CEASIOM from the design variables of a wing. Estimates of mass are made from semi- empirical formulas adapted to the geometry of the BWB and calculations centering and inertia are possible through BWB model developed in CATIA. Low fidelity methods, such as TORNADO and semi- empirical formulas are used to analyze the aerodynamic performance and stability of the aircraft. The aerodynamic results are validated using a high-fidelity analysis using FLUENT CFD software. An optimization process is implemented in order to obtain improved while maintaining a feasible design performance. It is an optimization of the plan form of the aircraft fuselage integrated with a number of passengers and equivalent to that of a A320.Les performance wing aircraft merged optimized maximum range are compared to A320 also optimized. Significant gains were observed. An analysis of the dynamics of longitudinal and lateral flight is carried out on the aircraft optimized BWB finesse and mass. This study identified the stable and unstable modes of the aircraft. Thus, this analysis has highlighted the stability problems associated with the oscillation of incidence and the Dutch roll for the absence of stabilizers.