Flutter Based Aeroelastic Optimization of an Aircraft Wing with Analytical Approach
CHALLENGE - An analytical flutter prediction methodology employing assumed mode technique for three dimensional wing and wing/store configurations is presented. The proposed method is used to investigate the flutter boundaries of well-known aeroelastic models, Goland and AGARD 445.6 wings.
SOLUTION - The flutter solution makes use of Lagrange formulation for aeroelastic modeling and Theodorsen function for aerodynamic load calculation. An aeroelastic optimization study with input parameters such as taper ratio, sweep angle, spanwise elasticity and shear modulus is performed to maximize flutter boundary of AGARD 445.6 wing and an optimum clean wing model is ascertained. An in-house solution code is developed for flutter analysis of Goland and AGARD 445.6 wing models. The flutter solution code is then coupled with the optimization software, modeFRONTIER, to perform aeroelastic design optimization of wing/store models as well.
BENEFITS - Optimization software modeFRONTIER and its available algorithm NSGA - II was used to perform the flutter based aeroelastic design optimization of an AGARD 445.6 wing. Flutter speed of initial design is 308.45 m/s with optimum design at 361.88 m/s meaning a 17.32 percent improvement.