Two raft wave energy converters: A combined optimisation of annual energy conversion and stability

Global warming has caused an increasing demand for renewable energy. Currently, 50% of the renewable energy is provided by wind and solar combined. However, these renewable energy sources are highly volatile. Wave energy converters can provide a stable renewable energy source. Previous research has contributed to understanding various combined...

Floating Spar Optimization: A constraint set investigation for the use of simulated annealing for substructure optimization

With the increase in need for offshore wind exploitation a research is set up with aims to develop a preliminary design tool. The introduction begins with background information on what role floating wind will play in the offshore wind industry and why this is a relevant topic. A general overview of floaters is presented with a comparison of the...

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...

Surrogate models for the characterization of hydrodynamic loads on perforated monopiles

Perforated monopiles show promise in providing a better alternative to the commonly used jacket-like substructures used in intermediate water depths in the range of 30 to 120 m. By introducing perforations near the vicinity of the splash zone the wave loads on the monopile can be mitigated and the fatigue damage reduced, which is the main...

Fatigue Safety Factors for Dynamic Power Cables: A reliability based approach

In contrast to traditional power cables for bottom-founded offshore wind turbines, power cables for floating wind turbines penetrate the water column and are exposed to cyclic loading. Due to the dynamic nature of the cable loading, the cables are prone to fatigue failure. Since the evaluation of the fatigue life of complex structures, like...

Wave damping by large-scale offshore kelp farms - A numerical modelling framework using a porous medium approach

Large-scale cultivation of seaweed presents opportunities for multiple global challenges currently at play. Cultivated seaweed can provide a sustainable source of protein for humans and cattle without competing for land, freshwater supply or the use of fertilisers. Kelp forests are known to be a solid basis for an elaborate biome that supports...

Hydroelastic Analysis of a Multi-Module Very Large Floating Structure

This thesis concerns a hydroelastic analysis of a multi-module very large floating structure (VLFS), analysed in the frequency domain. To this end, the fluid-structure interaction is described by a 2D model, where the VLFS is represented by four floating beams interconnected with rotational springs. The fluid is modelled as an ideal fluid, and...

Perforation of Monopiles to Reduce Hydrodynamic Loads and Enable use in Deep Waters

The offshore wind industry in Europe has experienced significant growth in the past decade, with wind farm development mostly focusing on the shallow area's in the North Sea. Naturally, the market is driven to reduce the Levelised Cost of Electricity (LCoE) to become more competitive with fossil fuels and less dependent on government subsidies....

Exploratory research on application Multi-Level Multi-Fidelity Monte Carlo in fluid dynamics topics: study on flow past a porous cylinder

In offshore engineering complex simulation models are constructed for design optimization using Monte Carlo methods. These models incur large computational costs. Multi-Level Multi-Fidelity Monte Carlo is proposed as a method to reduce the computational cost of these simulations. In addition, research is conducted on the use of porous media as...