A fixed point iteration approach for harmonic balance based aeroelastic computations
Presented is a fixed point iteration approach for harmonic balance computational flow solver based nonlinear aeroelastic computations. The methodology allows for the aeroelastic governing equations to be solved simultaneously, in an iterative manner, alongside the flow solver. The Newton-Raphson method is used at each iteration of the harmonic balance flow solver to solve for the aeroelastic governing equations solution variables based on the aerodynamic loading for the harmonic balance flow solution at the current harmonic balance flow solver iteration. Details of the approach are presented herein. Compared to the original harmonic balance flow solver based aeroelastic solution technique, which the authors developed over a decade ago, there is well over an order of magnitude computational speed-up for both the transonic airfoil aeroelastic configuration and cylinder in laminar cross-flow aeroelastic configuration presented in the paper.
