Flight Mechanical Modelling considering Flexibility and Flight Control Functions in Preliminary Aircraft Design

摘要

Next generation commercial transport aircraft need to be more fuel efficient than today's airliner. This leads to designs with lighter structures and thin wings with high aspect ratio. Consequently, the airframe becomes more flexible, which significantly impacts flight mechanical properties of the aircraft. Current methods for preliminary aircraft design are not accurate enough for flight mechanical assessments of such flexible aircraft and need to be improved. With better models in the early design stage that take the coupling of aeroelasticity, flight mechanics and flight control laws into account an accurate assessment is possible. This paper proposes a method to built a flight mechanical model of a commercial transport aircraft with flexible structure and flight control functions. The model allows detailed analysis of flight mechanical characteristics. The method starts from building a flight mechanical model using geometrical, structural and mass data of the aircraft. This model is then supplemented with automatically generated flight control laws and integrated into a flight simulation environment for conducting simulated flight tests. To demonstrate the capabilities of the method, two flight mechanical investigations are conducted. They show the impact of increased flexibility of a transport aircraft, which cannot be investigated with established pre-design methods.