Development and analysis of a combined tuned mass and tuned liquid damping system in a barge-like floating wind turbine structure

As offshore wind turbines are moving further from the coast, floating wind turbines are being considered. These structures need to be able to endure high dynamic loads while remaining as still as possible in order to minimize internal stresses and maximize the efficiency of the turbine. To find ways to combat large responses, the effectiveness...

Tangential load and trim behaviour: Analysis of the Maeslant Barrier under seaward flow

This investigation considers the two floating gates of the Maeslant barrier, which is a storm surge barrier in the Rotterdam area. During the end of each closure operation of the Maeslant barrier, the flow at the barrier may be in seaward direction. Three different effects have been observed in the situation with a flow in seaward direction. The...

Turn the Tide: A dive into the possibilities of sustainable water sports

This report will give an in depth view on the technical feasibility of placing an offshore platform from which watersports can be practiced in the waters surrounding the island of Bonaire. The feasibility research is done by appointment of two entrepreneurs on the island of Bonaire. The report will give an answer to the research question: Can an...

The implementation of Arctic ice management: Counteracting the annual Arctic sea ice loss by distributing sea water on top of sea ice

The Arctic is warming more rapidly than other latitudes, which can result in the release of additional greenhouse gasses, global sea level rise and increase in extreme weather events. Additionally, this causes the rapid decline of sea ice and an ice free Arctic might occur during the summer in the 2040s. The decreasing sea...

Ice-structure interaction in the Baltic Sea: defining a feasibility map for monopiles

The increasing popularity of offshore wind as a result of the demand for renewable energy, forces the industry to consider the development of wind farms in sub-arctic areas. One of these areas is the Baltic Sea, where the potential for wind energy is very large, but which is also prone to the occurrence of ice. For the design of offshore...

Impact of the Stiffness Characteristics of Wrapped Composite Joints on Eigenfrequencies of Wind Turbine Jacket Support Structures

This report investigates the influence of joint stiffness on the eigenfrequencies of offshore wind turbine supporting jacket structures. The joint is investigated individually, within the context of a jacket structure, and within the context of the entire offshore wind turbine structure. These analyses were specifically conducted for the case of...

Comparing different approaches to environmental contours for offshore wind turbine extreme response analysis

For marine structures subjected to combined wind and wave loads, predicting the long-term extreme response corresponding to a certain return period is an important aspect during the design stage. Generally, a full long-term analysis (FLTA) is recognized as a highly accurate method to determine the long-term extreme responses. FLTA integrates all...

Workability optimisation of the Stella Synergy: during monopile installation with a motion-compensated gripper and using its DP-system

Using a floating vessel operating on its DP-system and using a motion-compensated pile gripper to install monopiles could be the installation method of the future. Therefore, this thesis focuses on this method. The main objective of this thesis project is to build a model that accurately describes the motions of the Stella Synergy, the monopile,...

Fatigue in floodgates due to dynamic wave loading: A probabilistic design method

The ability to predict the fatigue of flood gates due to dynamic wave loading is becoming increasingly important as coasts and waterways worldwide are being reinforced to suit a changing climate. There are few comprehensive ways to do so however, which often leads to conservative estimates. This thesis presents an integral framework with which...

Workability of a Floating XL-Monopile Installation: A vessel motion study

In order to meet the climate goals to minimize the global temperature rise, an accelerated growth of renewable energy sources is necessary. Within the renewables market, the offshore wind sector takes a big part and has experienced a rapid growth over the past years. Around 80% of offshore wind turbines have a monopile foundation, (a large...

Early age cycling in the grout connection of an offshore wind jacket structure

The yearly installed percentage of offshore wind jacket substructures is rising. The most common installation method for a jacket structure nowadays starts by driving the foundation piles in the seabed through a pre-piling template. The jacket is then lowered on top until the legs are resting on the foundation piles through friction-based...

Prognosis and fault detection of drivetrains in medium-speed 10-MW Floating Wind Turbines

Premature failures in large offshore Wind Turbines are often attributed to bearing failure despite gearboxes being designed and developed using the best bearing design practices. Furthermore, as turbine size and rated power increase, bearings display an enhanced tendency to fail. Unscheduled bearing replacement at sea is a complex, costly,...

Buckling monopiles: The stability of a monopile based offshore wind turbine

Offshore wind turbines are being placed all over the world. The increased popularity of these structures comes with a boost to the development of wind turbines in general, resulting in larger and higher constructions. To ensure the support structures of the turbines are able to withstand the extreme loads and environmental conditions, it is...

Coupled Bending-Twist Vibration of a Horizontal Axis Wind Turbine Blade Accounting for Tower Shadow Under Turbulent Flow

Due to global warming effect humanity is forced to seek cleaner forms of energy. One of these are renewable energies, which are inexhaustible and increasingly competitive. More specifically wind energy is of highly importance due to its benefits. In order to achieve ultimate wind energy exploitation, the design of wind turbines should be...