Aeroelastic Aircraft Framework for the Design Performance Analysis of Composite Wings

Key technological challenges within the field of aeronautical engineering drive the design of wings to become increasingly lighter and more flexible. The added flexibility increases the influence of aeroelastic effects, which need to be incorporated in the preliminary design phase. To this end an aeroelastic tailoring tool for composite wing optimisation is developed by R. De Breuker et al. called Proteus. However, this design tool only assesses the wing, neglecting the wing's direct environment, the aircraft. The influence of the aeroelastic aircraft environment on the design performance of the wing is unknown and determining its significance is the topic of this thesis work. A standalone aeroelastic model of the complete aircraft has been developed as a proof of concept of the models and theories involved. To represent the aerodynamics of the aircraft, a source panel distribution placed on the fuselage wetted surface has been combined with a vortex-lattice method describing the wing and tail. This aerodynamic model is coupled to an Euler-Bernoulli beam based structural model of the aircraft. The resulting aeroelastic model is aeroelastically trimmed for static flight conditions. This is done with the use of sensitivities, omitting the need for an iterative trimmed aeroelastic equilibrium solution. The standalone aeroelastic model is verified with relevant test cases obtained from literature for both the aircraft aerodynamics and aeroelastic phenomena. The verification proves the concepts implemented and the aircraft aeroelasticity theories are added to the Proteus framework. The resulting formulation is again verified with the aforementioned test cases to ensure the correct implementation of the aircraft aeroelasticity. The expanded Proteus framework is used for the design performance analysis of an optimized composite wing on a real-life aircraft, the Common Research Model (CRM). The optimised wing design is obtained from the original Proteus tool to show the effect of the different aircraft parts on its design performance. The simulations are divided in wing-only, wing-fuselage, wing-tail and aircraft configurations to accurately determine the effect of the fuselage and tail on the design performance and trim conditions of the system. The four configurations are tested for three load cases: cruise, manoeuvre and pitch up and down loads. From the simulations performed it is deduced that the aeroelastic aircraft environment has a significant impact on the design performance of the optimized wing. The results prove that the influence of the aircraft and tail cannot be neglected during the structural design optimisation of the wing and when neglected creates a wing structure which is under-designed.