Development, Verification and Validation of 3DFloat; Aero-servo-hydro-elastic Computations of Offshore Structures

The aero-servo-hydro-elastic Finite-Element-Method code 3DFloat is tailored for nonlinear, coupled time-domain simulations of offshore structures in general and offshore wind turbines in particular. This article describes the theory behind the structural model, aerodynamic and hydrodynamic load modules, control system and coupling with an optimizer. The verification and validation history includes the IEA OC3/OC4/OC5 projects, two wave tank tests and participation in commercial projects. Current development examples include implementation of advanced hydrodynamics in the DIMSELO project, implementation of soil/structure interaction super-elements in the REDWIN project, and optimization of large rotors with sweep in an industry project.