Flutter prediction as currently practised is almost always deterministic in nature, based on a single structural model that is assumed to represent a fleet of aircraft. However, it is also recognised that there can be significant variability, even for different flights of the same aircraft. The safety factor used during flutter clearance is in part meant to account for this variability. Simulation tools can however represent the consequences of structural variability in the flutter predictions,

more »

... providing extra information which could be useful in planning physical tests and assessing risk. The main problem arising for this type of calculation when using high fidelity tools based on Computational Fluid Dynamics (CFD) is the computational cost. The current paper uses an eigenvalue based stability method together with CFD level aerodynamics and different methods for propagating structural variability to stability predictions. The propagation methods are Monte Carlo, perturbation and interval analysis. The feasibility of this type of analysis is demonstrated. Results are presented for the Goland wing and for a generic fighter configuration. I. NOMENCLATURE Symbols A Jacobian matrix b optimisation problem constraints d optimisation search direction E Young's modulus of elasticity g and G the first and second Jacobians of γi with respect to θ G shear modulus H optimisation objective function Hessian I moment of inertia L Lagrangian m r i the rth statistical moment of γi with respect to the θ p eigenvector q Lagrangian approximate quadratic approximate function R Residual vector of the fluid and/or structural model S Schur complement matrix t thickness w vector of fluid and/or structural unknowns V ar