Fluid–structure interaction simulation of flexible flapping foil for energy harvesting application using coupled open-source software tools

The influence of wing deformation on unsteady motion in fluids has drawn considerable attention across academic and industrial research, particularly in the fields of aerodynamics and hydrodynamics, due to its potential to enhance propulsion efficiency and inspire advanced engineering designs. This research addresses these complex dynamics by developing an advanced numerical tool that enables detailed analyses of moving deformable bodies in fluid environments. This initiative is crucial for advancing our understanding of fluid-structure interaction (FSI) phenomena and facilitating the design of bio-inspired systems for propulsion or energy harvesting. To investigate these dynamics, we developed a flexible approach that integrates advanced numerical tools for fluid-structure interaction analysis. Using a mesh motion tool based on a modified overset technique, this method incorporates the OpenFOAM fluid dynamics solver and the CalculiX structural solver, creating a comprehensive framework capable of capturing and analyzing the intricate fluid and solid interactions affecting moving deformable bodies. The reliability of this modified overset solver is validated through application to propulsion generation scenarios, specifically with a flapping foil case study, and by comparing the outcomes to established results in the literature [1], [2]. Additionally, this coupled FSI solver underwent critical validation by solving the benchmark Turek-Hron problem, demonstrating complete agreement with published results in [3]. We applied the solver to active-passive foils, incorporating active heaving motion and passive deformation. The results highlighted the significant impact of flexibility on energy harvesting. [1] M. A. Ashraf. Numerical simulation of the flow over flapping airfoils in propulsion and power extraction regimes. PhD thesis, UNSW Sydney, 2010.[2] S. Heathcote and I. Gursul. Flexible flapping airfoil propulsion at low reynolds numbers. AIAA journal, 45(5) :1066–1079, 2007.[3] S. Turek and J. Hron. Proposal for numerical benchmarking of fluid-structure inter-action between an elastic object and laminar incompressible flow. Springer, 2006.