Assessment of simulation codes for offshore wind turbine foundations
Övrigt - Master's Thesis, 2016
Offshore wind energy has the potential to become a leading renewable energy source. However, the cost of offshore wind turbine foundations is a major obstacle to the breakthrough of offshore wind energy development. There are a number of simulation codes that describe aerodynamic, hydrodynamic and serviceability response of offshore wind turbines. Nonetheless, each of these codes has its own limitations and capabilities in terms of; foundation type, environmental loading conditions as well as general modelling assumptions. Most simulation codes currently used in practice are limited to simple towers with monopile or gravity base foundations. However, they are being extended to model more developed foundation types, including tripods, jackets etc. Therefore, it is important to assess and judge the applicability of these codes to model such developed structures, which forms the purpose for this thesis.
To assess the capabilities and limitations of the studied simulation codes, principles and theories used were established. A classification of the codes was then made according to the observed principles. After that, three simulation codes (FASTv8, FOCUS6 and ASHES) were selected and examined through case studies with different types of foundations and loading conditions in order to study the codes practically. As expected, the results showed a variety of differences and similarities. In addition, some codes were more functional than others. For instance, in terms of the ability to describe loads with more advanced models, ability to create design load combinations etc.
In conclusion, it was confirmed that prior to choosing the appropriate simulation code for a given design, one has to consider the ability to describe the environmental conditions that the structure will face during its service life and the appropriate background required for the code to model the foundation.
Offshore wind energy