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...

Unsteady aerodynamics of floating offshore wind turbines under surge motion: A CFD analysis with openfoam

Due to its immense potential to harvest larger amounts of energy from the wind at a higher capacity factor, offshore wind energy is the key to reach the goal of a more sustainable future. The wind energy research community has been focusing all its efforts to bring the new concept of floating offshore wind turbines (FOWT) into the market. By...

Aerodynamic Design Optimization of Floating Wind Turbines for In Situ Hydrogen Production

The energy transition towards carbon neutrality requires a rapid electrification of all energy sectors by 2050. In the EU-27, the REPowerEU strategy, initiated in March 2022, is pursuing this target even more ambitiously. However, in order to achieve the aforementioned goals, the increasing demand for green hydrogen will...

Analysis the vortex ring state and propeller state of floating offshore wind turbines and verification of their prediction criteria by comparing with a CFD model

In our previous study, the vortex ring state (VRS) prediction criteria were introduced from helicopter's realm and applied to floating offshore wind turbines (FOWTs). The existence of the VRS on FOWTs was also successfully predicted. However, the prediction criteria we used have not been verified by comparing them with similar studies because...

The aerodynamics of floating offshore wind turbines in different working states during surge motion

The rotor of floating offshore wind turbines with platform motions may undergo different working states during its operation, e.g. from windmill working state to vortex ring and propeller working state. In this paper, an aerodynamic model based on a free wake vortex method is used to simulate the rotor undergoing surge motion. The associated...

Multidisciplinary design analysis and optimization of floating offshore wind turbine substructures: A review

The development of novel energy technologies to meet net zero carbon emission is essential in the provision of solutions to realize an increasing worldwide demand for renewable energy. Floating Offshore Wind Turbine (FOWT) is one of the emerging technologies to exploit the vast wind resources available in deep waters within the offshore wind...

CFD code comparison, verification and validation for decay tests of a FOWT semi-submersible floater

With the advancement of high-performance computation capabilities in recent years, high-fidelity modelling tools such as computational fluid dynamics are becoming increasingly popular in the offshore renewable sector. To justify the credibility of the numerical simulations, thorough verification and validation is essential. In this work,...

CFD study of induction and finite blade effect on a floating horizontal-axis wind turbine

As the need for abundant and reliable renewable energy increases, there is a growing interest in floating wind turbines, which would allow to harness the wind resource in areas where bottom-founded wind turbines cannot be used. However, the movements of the platform are expected to cause unsteady aerodynamics effects, including different wake...

Design of a suction pile multiline anchor system for floating offshore wind turbines

In this thesis I will show the realisation of a multiline anchor system using a suction pile anchor (SPA). From the literature research it can be concluded that the SPA is a suitable anchor for a multiline anchor system and that the most probable mooring configurations will be either the original single-line, the 3-line or the 6-line system....

Comparative analysis of different criteria for the prediction of vortex ring state of floating offshore wind turbines

The wind condition around floating offshore wind turbines (FOWTs) can be largely different from that developed around bottom-mounted wind turbines due to the platform motions. The existing literature identifies four working state of FOWTs, one of them being the vortex ring state (VRS) which may occur as the rotor moves in its own wake. It is...

Influence of Nonlinear Hydrodynamic Response on the Fatigue Damage of a FOWT: Development of Method to Assess Hydrodynamic Nonlinear Response of a FOWT, Having Allowance for Platform-Turbine Coupling Effects and Combined Wind and Wave Loads.

A method has been developed with which the rigid-body motions, stress and fatigue damage response of a TLP-type FOWT are determined in time domain, with the aim of assessing the influence of non-linear hydrodynamic response on the fatigue damage. The dynamics are described by means of a system of coupled 6DOF-EoMs and solved in Matlab, after...

Installation of a dynamic power cable for a floating offshore wind turbine: A comparative study

The latest Conference of Parties at Paris resulted in an important agreement that 27 percent of the total European energy consumption has to come from renewable energy in 2030. Offshore wind energy is an important resource for renewable energy. The shortage of shallow water areas pushed offshore wind farms into deeper waters. Floating Offshore...

Design and analysis of a semi-submersible floating wind turbine with focus on structural response reduction

Floating structures as spar, semi-submersibles and TLP have been proposed for offshore wind turbines for deep waters (>60m) according to the report of Arapogianni, Moccia, Williams, & Phillips (2011), where bottom fixed sub-structures are technically and economically not feasible. Several floating concepts have been designed and just some of...