Robust Aeroelastic Design Optimization of Wing/Store Configurations Based on Flutter Criteria

Abstract

We present a robust aeroelastic design optimization study for three dimensional wing/ store con gurations by employing an analytical utter analysis. The utter solution uses Lagrange equations with energy terms where structural displacements are represented by assumed mode technique and aerodynamic loads are calculated by Theodorsen function. An in-house utter code is developed parametrically in terms of design variables such as taper ratio, sweep angle, elastic axis location and material properties, and validated by using available reference data for well-known aeroelastic benchmark problems which are the Goland and AGARD 445.6 wing models. The utter code is coupled with an optimization software to perform deterministic design optimization of the AGARD 445.6 clean wing and then further developed to enable utter analysis and optimization of wing/store con gurations. The aeroelastic modeling counts for both structural and aerodynamic effects of external masses while couple of di erent optimization strategies are applied to determine optimum store locations and wing design to maximize utter speed. Finally, robustness criterion is implemented into aeroelastic optimization in the presence of structural uncertainties. These uncertainties are propagated by Monte Carlo Simulation (MCS) while 2 order Polynomial Chaos Expansion (PCE) is used through MCS to reduce the computational time.