Çok hafif bir uçağın statik ve dinamik aeroelastik analizleri

Aircraft design processes need to ensure that the aircraft is aeroelastically stable within its operational envelope. This thesis presents an overview of the static aeroelastic, flutter and gust response analysis of a very light aircraft. MSC.FlightLoads and MSC.Nastran are used for aeroelastic modeling and analysis. The methods to be used in the aeroelastic analysis of the VLA are tested on the AGARD 445.6 wing, and the results are in good agreement with the literature. Aeroelastic model corrections such as improvement of the aerodynamic solution, examining different aerodynamic modeling and aero-structure coupling approaches are implemented. Aerodynamic calculations are based on the Doublet-Lattice Method (DLM), which is the aerodynamic theory employed by Nastran for subsonic flows. The aerodynamic solution is improved by including the camber and the angle of incidence of the wing through the addition of an initial downwash. DLM-based loads are compared with loads obtained from computational fluid dynamics (CFD) analysis. The effects of DLM correction on the static aeroelasticity outputs are discussed. It is revealed by dynamic aeroelastic stability analysis that there is no flutter issue within the flight envelope. Matched point flutter solutions for various aileron stiffness are presented. Finally, the vertical acceleration response of the vehicle and internal structural response to the 1-cosine gust are analyzed. It is shown that the gust encountered at the cruise speed condition results in a higher vertical acceleration response than the limit maneuver load factors. Furthermore, tuned gust response analysis is conducted by tuning the gust velocity for different gust gradient lengths. Slightly higher responses than those found for the single gust gradient length required by CS-VLA [1] are captured at a shorter gradient length. Dynamic response analysis reveals that the response of the aircraft dies out in a short time and the model shows a dynamically stable behavior.