Unsteady aerodynamics and vortex shedding of a wind turbine blade

The thesis presents an analysis of unsteady vortex shedding and vortex induced vibrations (VIV) on wind turbine blades using a combination of Stereoscopic Particle Image Velocimetry (SPIV) and Computational Fluid Dynamics (CFD). A spanwise uniform blade with a symmetric NACA0021 airfoil section, 0.075 m chord, and 0.4 m span was tested...

CFD Simulation of a Floating Wind Turbine with OpenFOAM: an FSI approach based on the actuator line and relaxation zone methods

Floating offshore wind turbines (FOWTs) have the potential to harness wind resources in deepwater, which is so far prohibitive for conventional approaches. This, however, comes at a cost: the platform’s extra degrees of freedom (DoFs) introduce complex aerodynamic and hydrodynamic behaviours. Therefore, FOWTs must be accurately modeled to reduce...

Morphing a Straight-bladed Vertical Axis Wind Turbine Design: CFD-Based Analysis

Wind turbines have proven to be an essential part for the green energy mix. However, the focus was mainly on the horizontal axis wind turbines whereas the vertical axis wind turbine did not receive that amount of attention. In this work a straight-bladed vertical axis wind turbine (SB-VAWT) is explored which can temporary adjusts its rotor...

Aerodynamics of a 15-MW and a 5-MW Reference Wind Turbine Using Varying Fidelity Tools

The most effective way to decrease the cost of energy of wind turbines is to increase the rotor diameter. Therefore, this calls for the need of aerodynamic research on large wind turbines. This thesis project will tackle the topics addressed by the IEA Wind Task 47 which is focused on the aerodynamic analysis and comparison of the newly proposed...

A Comparative Study to Assess the Accuracy of the Lifting Line Code AWSM for Simulating Winglets on Wind Turbines

Wind turbine power output has grown massively over the past few decades, and this has been achieved in part by increasing the size of rotors. But the size of rotors is now limited by structural constraints as well as space constraints in wind farms. It is therefore important to use other innovative methods to increase wind turbine capacity...

An Investigation of Dynamic Stall using a LBM-VLES Approach

Horizontal Axis Wind Turbines (HAWTs) are a very popular source of renewable energy, but these machines are often subject to off-design conditions owing to the unsteady nature of wind. Unsteady aerodynamic conditions have been associated with cyclic loading of turbine blades, which can have hugely detrimental effects on their operational life....

On the aeroelasticity of an extreme scale wind turbine: Using an FSI framework in NLR's in-house code ENSOLV

Recent decades, an ongoing trend has emerged in the upscaling of wind turbines in order to compete with traditional energy resources. For conventional wind turbines, aside from improving safety, the driving factors for new designs have always been increased efficiency and performance. This has led to novel wind turbine designs comprising thin...

A CFD study of the Actuator Cylinder model

fastFoam - An aero-servo-elastic wind turbine simulation method based on CFD

The current wind turbine design tools are based on aerodynamic simulations using blade element momentum (BEM) codes to calculate loads and power, see for instance the tools HAWC2, Bladed or FAST. This engineering method is computationally efficient, but theoretically valid only for steady two dimensional flow in non-yawed conditions. <br/><br/...

Simulation Verification and Optimization of a Vertical Axis Wind Turbine using CFD

In this research computational fluid dynamics (CFD) is used to model a vertical axis wind turbine. Well known turbulence models | i.e. the k-epsilon and k-omega SST model | are used and compared in their performance against each other and a set of experimental data. The formal research question is "What models are available for the simulation of...