Numerical study on three-dimensional self-induced inverted flag

The current study aims to investigate the fluid–structure interaction (FSI) of flexible thin structures undergoing large displacements using numerical simulations. The primary case of interest is the self-induced inverted flag problem, which exhibits a rich set of coupled fluid–structure behavior and flapping dynamics. To achieve this, a new FSI algorithm is proposed via a partitioned approach. The proposed algorithm uses the remeshed-Vortex Particle Method (VPM) to resolve the flow and a finite element method-based elastodynamics solver to evaluate the response of the flexible structure. The remeshed-VPM algorithm is modified and extended in this study with new developments to enhance its applicability for complex FSI simulations of thin flexible structures. A multiresolution scheme is developed and applied in combination with the iterative Brinkman penalization method for remeshed-VPM. A new force formulation is introduced that is based on corrected penalization velocity, which can generate distributed body forces for the iterative Brinkman penalization method. Finally, the fully 3D remeshed-VPM is applied in conjunction with corotational beam formulation for FSI simulations of the inverted flag system. The FSI solver is utilized to conduct a series of simulations on the 2D and 3D inverted flag model, aiming to gain insights into the intricate dynamics of these fluid–structure interactions.