Efficient reduced-order aerodynamic modeling for fast prediction of transonic flutter boundary

Abstract

In this study, a reduced-order aerodynamic modeling framework by integration of a novel training data interpolation approach and the Eigensystem realization algorithm (ERA) is presented for fast prediction of transonic flutter boundary over a range of flight parameters. First, aerodynamic impulse responses are computed by using the technique of computational fluid dynamics (CFD) at grid points within parameter space, which are selected to cover the transonic regime of concern. Next, the training data interpolation approach by combining the discrete empirical interpolation method with the Kriging technique is used to generate the aerodynamic impulse response at arbitrary flight condition, without performing unsteady CFD simulations. Finally, the interpolated impulse response is used by ERA to extract the linear state-space aerodynamic model, which is coupled with the structural model for flutter characteristics analysis. To illustrate the proposed approach, a NACA 0012 airfoil of two degrees of freedom at zero mean angle of attack is investigated. The transonic flutter boundaries of the airfoil agree well with those obtained by using CFD-based technique.