Convergence acceleration to a periodic steady state for aeroelastic simulations

A structural model in the frequency domain is developed to obtain aeroelastic solutions of a NACA64A010 in the transonic regime. Results from a fully nonlinear frequency domain flow solver and the structural model are compared to a state of the art time accurate flutter code. The prohibitive cost of using time accurate methods to solve problems in transonic aeroelasticity is introduced and then followed by an analysis of using a Non-Linear Frequency Domain (NLFD) approach. The computational cost and accuracy associated with using the NLFD method are compared with already established time accurate methods. In this work, an accurate representation of the transonic flutter boundary is obtained and compared to pre-existing numerical results, further substantiating the NLFD method's ability to account for strong nonlinearities in the flow field. The flight conditions considered herein are of a swept wing in the transonic regime, a test case extensively studied by Isogai. This research has further validated the NLFD method as an accurate and efficient alternative for computing aeroelastic solutions in the transonic regime.