An improved, coupled frequency domain model for floating offshore wind turbines including aerodynamics, hydrodynamics and control

Modelling of Floating Offshore Wind Turbines (FOWTs) is challenging due to the strong coupling between the aerodynamics of the turbine and the hydrodynamics of the floating structure, which makes the dynamic response of the whole system highly complex. A variety of numerical approaches can be used to predict this response.<br/><br/>The frequency...

Assessment and analysis of hook mounted compensation methods for offshore wind turbine blade installation

During single-blade offshore wind turbine (OWT) installation, wind disturbance results in blade root motion. The sensitivity to this wind disturbance is more significant for larger blades, reducing the allowable installation weather limit. A potential solution is a Hook Mounted Compensator (HMC) between the crane and the load that can provide...

Mooring analysis for a TLP supporting a 15MW wind turbine: Identifying critical design parameters that influence the design life of a mooring system regarding higher-order loads for a TLP supporting a 15MW wind turbine

With the pressing matter of climate change, the importance of renewable energy sources is increasing day by day. A large portion of this renewable energy is to be generated with the use of wind turbines, which are commonly located onshore. In recent decades, great effort has been put in the development to place these turbines offshore, because...

Mooring system design, related to Pioneering Spirit: Improvement of a mooring system to secure a barge alongside Pioneering Spirit in offshore conditions, including an evaluation of the dynamic loads

Continuous development in the wind turbine industry leads to increasing size of wind turbines. Allseas investigates the possibility to enter the offshore wind turbine installation industry with Pioneering Spirit.<br/>For Allseas’ preliminary wind turbine installation design, wind turbines are assembled offshore, requiring wind turbine components...

Time Domain Modeling of a Point Absorber

The demand for renewable energies is rising due to climate goals and high oil prices. Not only the established renewable sources like wind and solar are interesting to exploit. There is a vast amount of energy stored in the world’s oceans. To harvest this energy, one needs a Wave Energy Converter (WEC). There<br/>are already some prototype WECs...

Operation considerations for pre-tensioning mooring systems’: Analysis of current pre-tensioning operations by analysing static and dynamic loads

In recent years, the demand for renewable energy has increased significantly because of its lower environmental impact than conventional energy technologies. As a result, wind power is one of the most important renewable energy sources. As land-based turbines have reached their maximum potential, recent market trends are moving into deeper waters...

Offshore Solar to Hydrogen System, Located North of Crete, Greece: A techno-economic assessment

The energy transition, is one of the most important topics nowadays. Renewable energy sources contribution in the energy mix is growing rapidly. However, due to their intermittent power output, they cannot ensure system security and stability, and therefore, energy storage technologies are needed. In this direction, hydrogen is an energy carrier...

An investigation of installation strategies to install next-generation offshore wind turbine generator components: Feedering vs. Shuttling, an efficient installation process for the future

Climate change is triggering among others a larger demand for offshore wind energy. This leads to new developments of which larger next-generation Wind Turbine Generators is the most relevant. These next-generation WTGs create problems for the carrying capacity of current-day installation jack-up vessels that work according to the conventional...

Hydroelastic wave deformation of Very Flexible Floating Structures: A performance study of a monolithic finite element model

At the moment, the world is at the verge of an energy transition. One of the most promising green resources is solar energy, which is a rapidly growing market. However, to fully use its potential of economy of scale, the application of offshore floating solar should be explored. A promising option is the use of a flexible type of Very Large...

Determination of safe mooring windows based on wind predictions

Feed forward control of U anti-roll tanks: Research on the effect of using a wave prediction system for the control of an active U anti-roll tank on the workability of an SOV operating at zero speed

Within this thesis an attempt is made to improve the seakeeping of a Service Operation Vessel (SOV) by means of an active anti-roll tank (ART). It is researched if the addition of a wave prediction system can improve the ART’s performance. As the seakeeping of the SOV is most important for the installed motion compensated gangway, the...

Framework to research and design wrinkle free very large flexible offshore solar platforms by adding permeability

Offshore solar power installations can be increased in size and efficiency compared to land based installations due to the availability of space and the cooling effect of water. To increase survivability in large waves, very large floating solar platforms can be made flexible. However, a flexible structure is susceptible to wrinkling due to...

Marine Diesel engine response to ventilation loads

Ventilation events are the result of masses of air being transported from the water surface along the hull, through the propeller plane. Previous research in literature has shown that ventilation induces large and sudden variations of the load on the propeller. The response of the propulsion system had not been documented before. This is a...

Essentials in Coupled Dynamics of Floating Offshore Wind Turbines: A research on simplified modelling of a Floating Offshore Wind Turbine

At the moment, offshore wind is an indispensable source of energy. Compared to onshore wind, wind speeds offshore are considerably higher and more constant. Furthermore, offshore wind turbines reduce noise and visual impacts. In contrast to fixed bottom foundations, floating wind can be economically feasible in global offshore waters that exceed...

Mild-Slope Wave Modelling for Dynamic Mooring Analyses: An exploratory study into an efficient alternative to the wave penetration model

Moored vessels in harbours around the world are affected by waves penetrating into the port basin. Hydraulic conditions can lead to severe vessel motions that influence the (un)loading efficiency and can even lead to the failure of fenders and mooring lines, creating unsafe situations for operating staff and <br/>A DMA is a chain of numerical...

Zero-emission double ended ferries: A concept exploration study

The goal of this thesis has been to develop a concept exploration tool for zero-emission double ended ferries, that determines the feasibility of different energy systems, creates corresponding design parameters and helps decide between zero-emission energy types. <br/><br/>The research goal was achieved in three steps. Firstly, knowledge was...

Winning at sea: Developing a method to provide insight in early stage naval fleet design requirements.

This thesis research focusses on winning at sea. "Winning at sea" requires presence of relevant capability at the right time and for the required time. A winning fleet is a fleet that has the capability to achieve this. The goal of this research is to define a winning fleet and to create a method that can provide insight in how such a fleet can...

Optimization of a submarine propulsion system by implementing a PEM fuel cell and a PMSM in a first principle model

A naval submarine has to cope with different operational modes: sailing at<br/>the surface, just below the surface or fully submerged and at different speeds.<br/>Therefore it needs an appropriate power plant. In this research a first principle<br/>submarine propulsion model has been extended with a Proton Exchange Membrane<br/>Fuel Cell (PEMFC)...