Coupled analyses capabilities in Semar

Offshore wind components and operations

Analysis models of offshore wind systems are often referred to as aero-hydro-servo-elastic models, as those four physical domains must usually be coupled in the same model. In brief, this is because we have to include both loads, controls and elastic deformations in the simulation. Aerodynamic loads act on the blades and tower. Hydrodynamic loads act on the support structure, mooring and cabling. Servomotors are used to pitch the blades according to the control system. Finally, elastic deformations in the whole system cause stresses that must be within thresholds.

Components design for an offshore wind turbine system can include support structure, mooring, dynamic cable, cable protection, and so on. Marine operations for an offshore wind farm can include transport and installation (T&I), lifting of cargo or personnel between vessel and turbine, connect/disconnect mooring, and heavy maintenance operations where for example a blade or generator is replaced. Both component design and marine operation planning often requires the full, or parts of, the aero-hydro-servo-elastic models to derive loads, motions, or other relevant responses.



We use Orcaflex for most of our analysis models, Python or excel for pre/post-processing and Python for controller implementation and other interactions with the simulation. Benefits of Orcaflex is a library of available turbines and support structures, and a neat interface with Python which allows quick implementation as well as high flexibility.



The hydrodynamics department in Semar currently consists of six engineers with MSc or PhD within hydrodynamics, mechanics and similar engineering fields. This large in-house team with experience from in-depth physics and coding to real-life offshore projects, ensures we deliver realistic and quality assured results. We can assemble and adapt existing models or build them up from scratch. We have a library of real-life vessels in our database in addition to the Orcaflex library. Our experience includes T&I of Hywind Tampen, implementing new turbines and controllers in Orcaflex, assessing heavy maintenance operations, and much more.