Wing Flutter Simulations Using an Aeroelastic Solver Based on the Predictor—Corrector Scheme

Abstract

An integrated computational fluid dynamics (CFD) and computational structural dynamics (CSD) method is developed here for the calculation and analysis of wing flutter in the time domain. The CFD solver is based on an unsteady multi-grid finite-volume algorithm for the Euler/Navier—Stokes equations on a multi-block structured grid. The CSD solver adopts a linear multi-step method to integrate the aeroelastic governing equations expressed in the modal space. A grid deformation method employing a radial basis function approach is introduced here to generate a dynamically moving grid. The solving procedure of an aeroelastic system is implemented with a predictor—corrector scheme in the physical time. By extrapolating the aerodynamic force, the hybrid predictor—corrector scheme is introduced to save the flow calculation right before the correcting step. The coupled CFD—CSD method is used to simulate wing flutter problems in the time domain in order to predict the stability of an aeroelastic system, which, in this paper, is fulfilled by finding the flutter boundaries. The calculation of the Isogai wing finds an S-shaped flutter boundary, which has been predicted by other studies. The obtained flutter boundary of the AGARD 445.6 wing shows a distinct transonic dip, which agrees well with the experiment result. Computational efficiency and accuracy using two predictor—corrector algorithms and a strong coupling algorithm are also compared.