SOWFA, FAST and OpenFOAM codes for Floating Of-Shore Wind Turbines (FOWT) fields simulation
The aim of this thesis is to investigate and present some open-source software for wind energy application. In particular the intention was to implement on a super-computer all the simulation tools required for the analysis of floating of-shore wind turbines (FOWT) as HydroDyn, OpenFAST and SOWFA. The main result are procedures and guidelines to implement steady-wind and real-wind simulations using the NREL 5 MW Reference turbine model and the mentioned software. Those instruments are presented, explained and evaluated for their possible application to on-shore, of-shore and deep-of-shore (floating) wind farms. The simulation procedure is presented with many details regarding scripts and variable declaration learned trough tens of debug runs. The NREL 5 MW has been modelled together with the OC4 Semi-submersible platform and the structure RAO has been investigated trough HydroDyn varying the incoming wave direction. A spectral analysis has been made considering more than 30 degrees of freedom and studying natural frequencies coupling respect to perturbations on the platform displacements. The same simulation set-up was used with both stand-alone SOWFA and SOWFA coupled with OpenFAST and HydroDyn to study differences in the output precision. Differences are produced by the aero-elastic behaviour of the turbine and by the floating platform motion. In conclusion, this work provides deep comprehension of already mentioned software capabilities and usage.