Efficient flutter prediction based on Harmonic Balance and V-g methods

An efficient flutter prediction method is proposed and applied in the analysis of transonic flutter boundary and influences of structural parameters. Based on frequency domain flutter analysis V-g method, an artificial damping term is applied to aeroelastic system to maintain harmonic motion. Thus, the frequency domain structural dynamic equations can be obtained. The aerodynamic describing function matrices can be acquired efficiently by harmonic balance method at a variety of harmonic frequencies. Combining aerodynamic describing function matrices and frequency domain structural equations, the aeroelastic stability problem can be transferred into a generalized eigenvalue problem. It is demonstrated that the flutter boundary of this method conforms with high-fidelity time-marching method and the analysis efficiency improves significantly. Moreover, when the structural parameters change, new flutter boundary can be easily obtained by generalized eigenvalue analysis in this method, other than time-marching method which needs numerous CFD/CSD coupled simulations.