Speaker
Description
Floating offshore wind turbines (FOWTs) couple large-amplitude rigid-body motion, strongly nonlinear free-surface hydrodynamics and mooring line dynamics, and their reliable design requires numerical tools that resolve all three simultaneously. This work presents a numerical framework that demonstrates two semi-submersible platforms with experimental data: the OC5-DeepCwind platform tested at MARIN, and the INO WINDMOOR prototype tested in the SINTEF Ocean Basin. The numerical model is built in the open-source hydrodynamics framework REEF3D::CFD, which solves the incompressible RANS equations on a staggered rectilinear grid with fifth-order WENO convection and third-order TVD Runge-Kutta time stepping, and captures the air-water interface with the level-set method. A direct-forcing immersed boundary method (DF-IBM) is used for wave loads on floating objects. The solid is represented by an arbitrarily complex STL geometry converted into a signed distance field by ray casting, so that no dynamic or overset meshes are needed. Six-degree-of-freedom (6DOF) motion is calculated with Euler parameters and Hamiltonian mechanics, which can handle arbitrarily large motions. Two mooring models are coupled to the same rigid-body solver, a native finite-element quasi-static model and the lumped-mass dynamic model MoorDyn, for reliable mooring force calculations. The numerical results show good agreement with the experimental data and demonstrate the capabilities of the model for floating-body simulations in waves.
| Topic Area | Advanced Computational Methods and Applications in Marine, Subsea and Offshore Technology |
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