Searched for: subject:"Wake"
(1 - 20 of 132)

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Doekemeijer, B.M. (author)
Open-loop wake steering inconsistently improves the energy yield of wind farms in field experiments in the literature. This thesis matures wind farm control technologies for power maximization in a model-based closed-loop framework towards real-world practical applicability. Firstly, open-loop wake steering is evaluated on a commercial onshore...
doctoral thesis 2020
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van Beek, M.T. (author)
Wind farms experience significant efficiency losses due to the aerodynamic interaction between turbines. A possible control technique to reduce these losses to a minimum is yaw-based wake steering. This thesis investigates the feasibility of this technique by calibrating a surrogate model called the FLOw Redirection and Induction in Steady-state...
master thesis 2020
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Keijer, W.J.T. (author)
The vertical axis wind turbine (VAWT) concept in its current, fixed-pitch iteration is hindered by lower aerodynamic efficiency compared to existing horizontal axis wind turbines. Implementing a form of circulation control on the VAWT by actively pitching the blades throughout the turbine’s rotation could potentially enhance power capture...
master thesis 2020
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van Binsbergen, Diederik (author)
Power optimization through wake steering and axial induction control is a well investigated topic in wind energy, which is generally proven to work. The influence of control manoeuvres on the fatigue of static components is generally discussed, but drivetrain fatigue due to wake steering and axial induction control is rarely discussed, while it...
master thesis 2020
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Chandramouli, P. (author), Memin, Etienne (author), Heitz, Dominique (author)
We present a variational assimilation technique (4D-Var) to reconstruct time resolved incompressible turbulent flows from measurements on two orthogonal 2D planes. The proposed technique incorporates an error term associated to the flow dynamics. It is therefore a compromise between a strong constraint assimilation procedure (for which the...
journal article 2020
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Willemsen, Maurice (author)
We consider a system of IoT nodes powered completely by energy harvesting.This work focuses on achieving the time correlation of data measurements ina network of energy harvesting sensor nodes. Time correlation is achieved byhopping a message through the whole network. This message wakes up all thenodes and lets them perform a measurement....
master thesis 2020
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Voogd, Alan (author)
This thesis experimentally assesses the benefit of Boundary Layer Ingestion (BLI) at the unaccelerated condition (thrust equals drag) of an integrated system in an industrial wind tunnel setting. The boundary layer or wake flow of the fuselage is ingested by the propulsor. Previous research shows that ingesting the boundary layer can lead to...
master thesis 2020
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Doekemeijer, B.M. (author), van der Hoek, D.C. (author), van Wingerden, J.W. (author)
Wind farm (WF) controllers adjust the control settings of individual turbines to enhance the total performance of a wind farm. Most WF controllers proposed in the literature assume a time-invariant inflow, whereas important quantities such as the wind direction and speed continuously change over time in reality. Furthermore, properties of the...
journal article 2020
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Qu, Y. (author), Metrikine, A. (author)
In this paper, a new wake oscillator model with nonlinear coupling is proposed for the modelling of vortex-induced vibration. The purpose is to develop a model that is capable of reproducing both free and forced vibration experiments. To achieve this goal, an existing van der Pol wake oscillator model is first reviewed. The limitations of the...
journal article 2020
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Qu, Y. (author), Metrikine, A. (author)
In this study a new wake oscillator model is proposed to describe the coupled cross-flow and in-line vortex-induced vibrations of an elastically supported rigid cylinder. Different from many other studies where two wake oscillators have been applied, the current model uses only one wake oscillator coupled to both cross-flow and in-line motions....
journal article 2020
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Li, B. (author), Basu, S. (author), Watson, S.J. (author), Russchenberg, H.W.J. (author)
In the near future, wind and solar generation are projected to play an increasingly important role in Europe's energy sector. With such fast-growing renewable energy development, the presence of simultaneous calm wind and overcast conditions could cause significant shortfalls in production with potentially serious consequences for system...
journal article 2020
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Itoh, E (author), Mitici, M.A. (author)
Although the application of new, reduced aircraft separation minima can directly increase runway throughput, the impact thereof on the traffic flow of aircraft arriving at the destination airport has not been discussed yet. This paper proposes a data-driven and queue-based modeling approach and presents an analysis of the impact on the delay...
journal article 2020
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Seitz, Arne (author), Luisa Habermann, Anaïs (author), van Sluis, M. (author)
The paper discusses optimality constellations for the design of boundary layer ingesting propulsive fuselage concept aircraft under special consideration of different fuselage fan power train options. Therefore, a rigorous methodical approach for the evaluation of the power saving potentials of propulsive fuselage concept aircraft...
journal article 2020
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Kassem, Ahmed Valentin (author)
The modelling of gust generation by an array of oscillating vanes at Delft's University of Technology Open Jet Facility is proposed. Focus is placed on identifying relevant in-field gusts that horizontal axis wind turbines are exposed to and reproduction via numerical methods in the wind tunnel setting. A computationally efficient model is...
master thesis 2019
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Kaveripuram Ramasamy, Shravan Raaghav (author)
Multi-phase flows are ubiquitous in nature and in everyday life surrounding us, impacting us in almost all possible ways. The presence of particles in a flow can change the flow behaviour in an unpredictable manner. The simplest example of a particle-laden flow, that one can think of, is the settling of a single sphere under gravity in a...
master thesis 2019
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Ramakrishnan, Pooja (author)
In the coming decade, the Dutch government plans to broadly expand its wind farm real estate over the North Sea region. This is a significant undertaking because, from literature, it is understood that wind turbines can affect the local environment. These impacts include, but are not limited to, changes in variables such as wind speed and...
master thesis 2019
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Dong, J. (author), Viré, A.C. (author), Ferreira, Carlos (author), Li, Zhangrui (author), van Bussel, G.J.W. (author)
A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine, which is divided into two parts. The near wake model uses a blade bound vortex model and trailed vortex model, which is developed based on vortex filament method with straight lifting lines assumption. By contrast, the far...
journal article 2019
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Langor, Erin (author)
As the penetration of offshore wind farms continues to increase in Western Europe, the North Sea in particular is becoming more densely populated by offshore wind farms. Wind turbine wakes have been a topic of great research in the field of wind energy for some time, however the industry now seeks an understanding of the in- fluence of the wake...
master thesis 2019
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Duffy, Patrick (author)
The engineering flow models used to estimate annual energy production (AEP) in offshore wind farm layout optimization typically assume inflow homogeneity over the model domain. This assumption lies in contrast with observations of horizontal wind speed gradients in coastal regions where many offshore wind farms are being constructed. Accounting...
master thesis 2019
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Muller, Jelle (author)
The offshore wind industry has grown rapidly over the last decade and drivetrains are increasing in size to reduce the cost of energy. These turbines are operating in a harsh environment. Adopting a preventive maintenance strategy is important to achieve an as high as possible availability of the farm and reduce the cost of maintenance. A well...
master thesis 2019
Searched for: subject:"Wake"
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