Abstract:

A new expression of multiplicative perturbation to dynamic pressure is presented based on the robust flutter analysis method. The flutter system augmented with dynamic pressure uncertainty is formulated into a μ framework directly using frequency domain aerodynamics, which makes use of frequency domain μ analysis to predict the critical flutter point. The conditions for the local maximum of μ at the critical flutter point are derived and the algorithm is expounded in detail. This new method can eliminate the paradox in the classical flutter solutions that use frequency domain aerodynamics to solve the flutter eigenvalues in complex frequency domain. Moreover, this method does not need to solve flutter eigenvalues, thus eliminating the possible branchcrossing problem. Numerical examples demonstrate that the proposed method can give as accurate flutter results as those obtained by classical flutter solutions, which suggests that it can be applied to engineering flutter analysis.

Key words: flutter, μ analysis, multiplicative uncertainty, dynamic pressure perturbation, frequency domain