Demonstration of a coupled floating offshore wind turbine analysis with high-fidelity methods

• The paper presents an advanced method for simulating off-shore wind turbines.
• CFD, Multi-Body Dynamics (MBD) and Smoothed Particle Hydrodynamics (SPH) were used.
• An offshore wind turbine configuration is put forward as a test case.
• The coupling methods between the CFD, MBD and SPH are presented and investigated.
• The proposed coupling works well as a numerical tool.
• The need for some test data for such complex systems is highlighted.

This paper presents results of numerical computations for floating off-shore wind turbines using, as an example, a machine of 10-MW rated power. The aerodynamic loads on the rotor are computed using the Helicopter Multi-Block flow solver developed at the University of Liverpool. The method solves the Navier–Stokes equations in integral form using the arbitrary Lagrangian–Eulerian formulation for time-dependent domains with moving boundaries. Hydrodynamic loads on the support platform are computed using the Smoothed Particle Hydrodynamics method, which is mesh-free and represents the water and floating structures by a set of discrete elements, referred to as particles. The motion of the floating offshore wind turbine is computed using a Multi-Body Dynamic Model of rigid bodies and frictionless joints. Mooring cables are modelled as a set of springs and dampers. All solvers were validated separately before coupling, and the results are presented in this paper. The importance of coupling is assessed and the loosely coupled algorithm used is described in detail alongside the obtained results.