Error-Based Adaptive Time Integration for Midfidelity Aeroelastic Simulations

Accurately simulating aeroelastic systems at low computational cost is challenging, especially for slender structures exhibiting nonlinear behavior. Coupling geometrically exact beams with the unsteady vortex lattice method offers an attractive balance between accuracy and efficiency. However, robustness can be challenged under large displacements, rotations, or rapidly changing flow conditions. In many cases, convergence can only be reached by using very small time steps, which significantly increases computational costs, limiting the applicability in design processes. To address this, we introduce a method for local error estimation that enables adaptive time-step control. The approach combines Richardson’s extrapolation with an improved approximation of aerodynamic forces, allowing the determination of a higher-order reference solution and thus an error estimation. We show that approach can enhance the robustness of the framework. As a side effect, reducing computational costs is possible since fewer time steps are required and no separate convergence study is necessary. The proposed scheme is demonstrated on nonlinear examples. The implementation is user-friendly, requiring only a small number of parameters to be set. The proposed error estimation strategy can be easily transferred to other implementations and combined with different time-step adaptation algorithms.