LCO Flutter Instability on Oscillating Supersonic Wing by Means of Linearized Aerodynamic Small Disturbance Theory

Abstract

This article offers an optimization procedure in designing much lighter supersonic wing by employing a composite structure by constraining the structural persistence due to flutter speed, a type of aeroelasticity failure. The application of composite material in aeroelasticity contributes to the changes in the expected flutter speed. The composite material such that graphite/epoxy gives high modulus compared to the metallic material such as aluminium where the structural flexibility could be improved. In contrast, the structural weight could be reduced through the optimization process. Technically, an optimization procedure that is utilizing the aeroelastic parameter as a constraint is called aeroelastic tailoring. In this paper, the objective of this tailoring process is to optimize the wing weight while maintaining the flutter boundaries, where the wing design adopted in this research has been analyzed at sea level. As the optimization process is on-going, the flutter speed and the plate manufacturing thickness become the restriction in the wing weight reduction. The investigation shows good agreement to the objective where the removal of weight for the High Modulus (HM) graphite/epoxy wing skin for the skin weight, clean wing and total wing with missile launcher external stores are 75.82%, 61.96% and 22.09%, respectively compared to the baseline aluminium wing model. For the tailoring process, it is found that the flutter Mach number increases more than 81% using as the Graphite/epoxy composite replaced the aluminium as the skin.