Exploring alternative ocean energy conversion solutions: SPH-based solver for flexible wave energy converters

Long-standing unresolved issues affect wave energy converters (WECs) development, such as uncertainties about performance and reliability. An interesting alternative to reduce operational and manufacturing costs is offered by flexible WECs (FlexWEC), which are meant to accommodate ocean waves and related loads with compliant structures, while providing improved absorption capabilities on a wide spectrum of frequencies. With embedded distributed power take-off systems, also the design process would be slimmed down significantly. To aid the development of such technologies, high-fidelity models can play a crucial role, being able to handle the complex hydroelastic problem at stake. In this work we propose a Lagrangian computational fluid dynamics (CFD)-based approach for simulating flexWECs, leveraging the open-source DualSPHysics solver coupled with the Project Chrono library. Based on the Smoothed Particles Hydrodynamics (SPH) method, this framework offers notable advantages in simulating free surface flows and dynamic wave-structure interaction. A co-rotational dynamic method grounded on lumped elastic discretization reproduces the dynamics of fully flexible beams or plates, being inherently suitable for nonlinear FSI. The development of high-fidelity design instruments is expected to significantly enhance the modeling perspectives of a variety of offshore structures, becoming a key instrument for the future of offshore energy islands.