scholarly journals Review of tidal turbine wake modelling methods

2020 ◽  
Vol 3 (2) ◽  
pp. 91-100
Author(s):  
Ellen Jump ◽  
Alasdair Macleod ◽  
Tom Wills
Keyword(s):  
Physical Modelling ◽  
Tidal Energy ◽  
Horizon 2020 ◽  
Wake Interactions ◽  
Tidal Turbine ◽  
Modelling Techniques ◽  
Turbine Wake ◽  
Modelling Methods ◽  
Optimal Site ◽  
Device Modelling

Enabling Future Arrays in Tidal (EnFAIT) is an EU Horizon 2020 flagship tidal energy project. It aims to demonstrate the development, operation and decommissioning of the world’s largest tidal array (six turbines), over a five-year period, to prove a cost reduction pathway for tidal energy and confirm that it can be cost competitive with other forms of renewable energy. To determine the optimal site layout and spacing between turbines within a tidal array, it is essential to accurately characterise tidal turbine wakes and their effects. This paper presents a state-of-the-art review of tidal turbine wake modelling methods, with an overview of the relevant fundamental theories. Numerical and physical modelling research completed by both academia and industry are considered to provide an overview of the contemporary understanding in this area. The scalability of single device modelling techniques to an array situation is discussed, particularly with respect to wake interactions.

scholarly journals Towards a turbulence characterization in tidal energy sites. First results of THYMOTE project

2019 ◽  
Vol 261 ◽  
pp. 05002 ◽  
Author(s):  
Sylvain Guillou ◽  
Jean-François Filipot ◽  
Jérôme Thiébot ◽  
Grégory Germain ◽  
Nicolas Chaplain ◽  
...  
Keyword(s):  
Free Surface ◽  
Numerical Modelling ◽  
Physical Modelling ◽  
Field Measurements ◽  
Tidal Energy ◽  
Turbulence Level ◽  
High Current ◽  
First Results ◽  
Tidal Turbine ◽  
High Turbulence

Tidal turbine will be installed in area with high current and high turbulence level. A characterisation of this last is required. The aim of the project THYMOTE is to characterize and understand the generation of eddies from smaller to several tens of meters. Three technics are used: Numerical modelling, Physical modelling, field measurements. Physical and numerical modelling show clearly the appearance of the eddies close to the bottom in presence of dunes or rocks and their motion towards the free surface.

scholarly journals Recent Developments in the Modelling of Transformer Windings

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2798
Author(s):  
Konstanty M. Gawrylczyk ◽  
Szymon Banaszak
Keyword(s):  
Literature Review ◽  
Research And Development ◽  
Frequency Response ◽  
Input Data ◽  
Recent Developments ◽  
Modelling Techniques ◽  
Lumped Parameters ◽  
Wave Phenomena ◽  
Modelling Methods ◽  
Direct Calculations

The paper provides a review of the modelling techniques used to simulate the frequency response of transformer windings. The aim of the research and development of modelling methods was to analyze the influence of deformations and faults in the windings on the changes in the frequency response. All described methods are given with examples of the modelling results performed by the authors of this paper and from literature sources. The research is prefaced with a thorough literature review. There are described models based on lumped parameters with input data coming from direct calculations based on the winding geometry and obtained from FEM modelling software and models considering the wave phenomena in the windings. The analysis was also performed for practical problems in winding modelling: the influence of windings other than the modelled one and the influence of parallel wires in a winding.

scholarly journals Experimental analysis of the shear flow effect on tidal turbine blade root force from three-dimensional mean flow reconstruction

2020 ◽  
Vol 378 (2178) ◽  
pp. 20200001 ◽  
Author(s):  
B. Gaurier ◽  
Ph. Druault ◽  
M. Ikhennicheu ◽  
G. Germain
Keyword(s):  
Turbine Blade ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Velocity Shear ◽  
Reconstruction Method ◽  
Mean Flow ◽  
Blade Root ◽  
Image Velocimetry ◽  
Tidal Turbine

In the main tidal energy sites like Alderney Race, turbulence intensity is high and velocity fluctuations may have a significant impact on marine turbines. To understand such phenomena better, a three-bladed turbine model is positioned in the wake of a generic wall-mounted obstacle, representative of in situ bathymetric variation. From two-dimensional Particle Image Velocimetry planes, the time-averaged velocity in the wake of the obstacle is reconstructed in the three-dimensional space. The reconstruction method is based on Proper Orthogonal Decomposition and enables access to a representation of the mean flow field and the associated shear. Then, the effect of the velocity gradient is observed on the turbine blade root force, for four turbine locations in the wake of the obstacle. The blade root force average decreases whereas its standard deviation increases when the distance to the obstacle increases. The angular distribution of this phase-averaged force is shown to be non-homogeneous, with variation of about 20% of its time-average during a turbine rotation cycle. Such force variations due to velocity shear will have significant consequences in terms of blade fatigue. This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.

scholarly journals Passive acoustic methods for tracking the 3D movements of small cetaceans around marine structures

2020 ◽  
Author(s):  
Douglas Gillespie ◽  
Laura Palmer ◽  
Jamie Macaulay ◽  
Carol Sparling ◽  
Gordon Hastie
Keyword(s):  
Marine Mammals ◽  
New Technologies ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Time Of Arrival ◽  
Marine Animals ◽  
Tidal Turbines ◽  
Wide Range ◽  
Tidal Turbine ◽  
Passive Acoustic

AbstractA wide range of anthropogenic structures exist in the marine environment with the extent of these set to increase as the global offshore renewable energy industry grows. Many of these pose acute risks to marine wildlife; for example, tidal energy generators have the potential to injure or kill seals and small cetaceans through collisions with moving turbine parts. Information on fine scale behaviour of animals close to operational turbines is required to understand the likely impact of these new technologies. There are inherent challenges associated with measuring the underwater movements of marine animals which have, so far, limited data collection. Here, we describe the development and application of a system for monitoring the three-dimensional movements of cetaceans in the immediate vicinity of a subsea structure. The system comprises twelve hydrophones and software for the detection and localisation of vocal marine mammals. We present data demonstrating the systems practical performance during a deployment on an operational tidal turbine between October 2017 and October 2019. Three-dimensional locations of cetaceans were derived from the passive acoustic data using time of arrival differences on each hydrophone. Localisation accuracy was assessed with an artificial sound source at known locations and a refined method of error estimation is presented. Calibration trials show that the system can accurately localise sounds to 2m accuracy within 20m of the turbine but that localisations become highly inaccurate at distances greater than 35m. The system is currently being used to provide data on rates of encounters between cetaceans and the turbine and to provide high resolution tracking data for animals close to the turbine. These data can be used to inform stakeholders and regulators on the likely impact of tidal turbines on cetaceans.

Effects of turbulence modelling in AD/RANS simulations of single wind & tidal turbine wakes and double wake interactions

Energy ◽  
2020 ◽  
Vol 208 ◽  
pp. 118440
Author(s):  
Linlin Tian ◽  
Yilei Song ◽  
Ning Zhao ◽  
Wenzhong Shen ◽  
Chunling Zhu ◽  
...  
Keyword(s):  
Turbulence Modelling ◽  
Wake Interactions ◽  
Tidal Turbine ◽  
Rans Simulations

scholarly journals Tidal current power effects on nearby sandbanks: a case study in the Race of Alderney

2020 ◽  
Vol 378 (2178) ◽  
pp. 20190503 ◽  
Author(s):  
Luke S. Blunden ◽  
Stephen G. Haynes ◽  
AbuBakr S. Bahaj
Keyword(s):  
Sediment Transport ◽  
Tidal Energy ◽  
Sand Wave ◽  
Sand Transport ◽  
Tidal Dynamics ◽  
Tidal Flows ◽  
Tidal Turbine ◽  
Turbine Arrays ◽  
Sediment Model

A validated numerical model of tidal flows and sediment transport around the Alderney South Banks was used to investigate the potential effects of large (300 MW) tidal turbine arrays at different locations in Alderney territorial waters. Two methods were used, firstly looking at hydrodynamic changes only and secondly modelling sediment transport over a non-erodible bed. The baseline hydrodynamic model was validated relative to ADCP velocity data collected in the immediate vicinity of the sandbank. Real-world sand transport rates were inferred from sand-wave migrations and agree favourably with sediment transport residuals calculated from model outputs. Outputs from the sediment model reproduced realistic morphological behaviours over the bank. Seventeen different locations were considered; most did not result in significant hydrodynamic changes over the South Banks; however, three array locations were singled out as requiring extra caution if development were to occur. The results provide a case for optimizing the array locations for twin objectives of maximizing array power and minimizing impacts on the sandbanks. This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.

Assessment of Zooplankton Injury and Mortality Associated With Underwater Turbines for Tidal Energy Production

2013 ◽  
Vol 47 (4) ◽  
pp. 142-150 ◽  
Author(s):  
David R. Schlezinger ◽  
Craig D. Taylor ◽  
Brian L. Howes
Keyword(s):  
Size Distribution ◽  
Particle Density ◽  
Collaborative Work ◽  
Tidal Energy ◽  
Energy Potential ◽  
Marine Renewable Energy ◽  
Tidal Turbines ◽  
Video Images ◽  
Significant Difference ◽  
Tidal Turbine

AbstractCollaborative work between the UMASS-Marine Renewable Energy Center, the Town of Edgartown, and the Coastal Systems Program is focused on developing the tidal energy potential of Muskeget Channel. We have undertaken detailed oceanographic and environmental surveys to optimize in-stream turbine power generation and to quantify potential environmental effects. In 2011 and 2012, tidal turbine demonstration projects were conducted in Muskeget Channel to determine the combined effects of blade strikes, shear stress, turbulence, and cavitation on zooplankton. Single turbines may minimally impact zooplankton populations; however, full-scale projects may potentially alter zooplankton populations forming the base of coastal food webs. Static plankton tows were performed up- and downstream of the operating turbine axis. Integral flow meters allowed adjustment of tow duration to optimize zooplankton density in the concentrate. Samples were held at in situ temperatures, and sequential photomicrographs and video images were taken to determine particle density, size distribution, and the number of live organisms in samples taken up and down gradient of the operating tidal turbines within 3 h of collection. Statistical analysis showed no significant difference in the total number or size distribution of motile zooplankters, indicating tidal turbine operation did not cause significant mortality and suggested that impacts of commercial size tidal energy projects upon zooplankton populations in Muskeget Channel may be negligible.

scholarly journals Simulation model of single structured tower hybrid wind and tidal energy cultivation based on Yemen’s south west coast

2019 ◽  
Vol 107 ◽  
pp. 01007
Author(s):  
Sadeq M. Alfakih ◽  
Tian De ◽  
Syed Jawad Ali Shah ◽  
Aneeq ◽  
Khuram Hayat
Keyword(s):  
Renewable Energy ◽  
West Coast ◽  
Cost Effective ◽  
Tidal Energy ◽  
Ocean Current ◽  
Energy Unit ◽  
Available Energy ◽  
South West ◽  
South West Coast ◽  
Tidal Turbine

This paper propose the single structured tower with hybrid renewable energy cultivation on south west coast of Yemen by the means of tidal turbine which uses ocean current under the ocean and at the top of tower is wind turbine to harvest the maximum available energy resources at the same site. This single structured turbine is an efficient and cost effective way to utilize the renewable resources available at the case study area of Yemen. The meteorological analysis is also considered to increase the efficiency of this renewable energy unit as well as the Matlab simulation of generation unit is being carried out to observe the behavior of renewable sources (wind, tide current) on turbine.

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