Effect of Wave-Current Interaction on Strong Tidal Current

2018 ◽  
Author(s):  
Aleksandar Jakovljević ◽  
Martin Dumont ◽  
Frédéric Dias
Keyword(s):  
Velocity Field ◽  
Energy Resource ◽  
Tidal Energy ◽  
Research Area ◽  
Stokes Drift ◽  
Area Of Interest ◽  
Time Period ◽  
Tidal Turbine ◽  
Wave Heights ◽  
Wave Energy Spectrum

We consider the influence of wave-current interactions (WCI) on the tidal energy resource through changes in the velocity field of tidal currents. In order to investigate this, we have run three models: SWAN (stand-alone), ROMS (stand-alone) and COAWST (two-way coupled ROMS and SWAN model). The research area of our studies is Alderney Race, France, an area with strong currents, which has a strong potential for tidal turbine deployment. The time period used for the simulations was March 2008, when a strong storm hit the Alderney Race area and produced significant wave heights (Hs) of up to 7 m and a Stokes drift near the surface close to 0.3 m/s. Furthermore, in order to see the extent of the influence of large waves on current parameters, two virtual storms with larger waves have been generated by magnifying the wave energy spectrum and changing the frequency of the spectrum of the real storm in March 2008. The 3D and the barotropic velocity field were analysed in order to see if the WCI in the waters of Alderney Race during storm conditions can cause a significant increase or decrease of the current speed and through which mechanisms. This study also investigates the Turbulent Kinetic Energy (TKE) in order to portray the turbulent conditions in the area of interest which are important for resource characterisation and device design.

Potential Area to Harness the Tidal Energy at West Coast Peninsular Malaysia

2015 ◽  
Vol 785 ◽  
pp. 637-641
Author(s):  
Mohd Zaifulrizal Zainol ◽  
Haziatul Najihah Zana Rahim ◽  
Wardiah Dahalan ◽  
Atzroulnizam Abu ◽  
Muhamad Fadli Ghani ◽  
...  
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
West Coast ◽  
Negative Impact ◽  
Average Power ◽  
Energy Resource ◽  
Tidal Energy ◽  
Peninsular Malaysia ◽  
Potential Region ◽  
Tidal Turbine

Malaysia nowadays depends heavily on conventional energy resource for generating electricity and transportation. This will give negative impact and trigger other problems if not well managed. Therefore, it is very important to increase the use of renewable energy especially the tidal energy as the tidal energy is more predictable and reliable renewable energy source. A kinetic energy produced by the tidal differences will be used to generate electricity and involves the use of a tidal turbine. There are two approaches that are being used to harness the tidal energy for the generation of electricity which are barrage approach and tidal stream approach. This paper identify the potential region along west coast of peninsular Malaysia that has higher potential power generation for harnessing tidal energy and study which approach suitable to be applied. From the results, show that the highest potential power generation for harnessing tidal energy is at Pelabuhan Klang with the average power availability is 591.19kW while the lowest is at Tanjung Keling with the average potential power generation is 52.75kW.

scholarly journals Tidal Energy Utilization of Larantuka Strait by Dual Tidal Turbines to Increase National Energy Resilience

2019 ◽  
Vol 2 ◽  
pp. 73-77
Author(s):  
Eko Soejianto ◽  
Khansa Hanifa Zahra ◽  
Suci Nur Hidayah
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Energy Resource ◽  
Electrical Energy ◽  
Tidal Energy ◽  
Ocean Currents ◽  
Energy Utilization ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
The Government

Currently, renewable energy can only support 5% of national energy needs. Meanwhile, in 2035 renewable energy targeted to sustain 14% of total national energy demand. The proper way for optimizing the renewable energy is needed to actualize the target. Tidal energy as one of the potentials that are still being developed and need more attention from the government. Tidal can be used for natural energy resource since it has zero emission, produce big energy, and has no impact to weather. Larantuka Strait located in Flores island, Nusa Tenggara Timur province can produce tidal velocity up to 2.859 m/s with water density as much as 1.025 gr/cc.  In utilizing this energy, we use new innovation by using dual tidal turbines which placed at the foot of Palmerah Bridge. The construction of Palmerah Bridge is built both by the government of Flores Island and Adonara Island. Dual tidal turbines are more efficient than singl e turbine by reason of tidal that has passed through the first turbine can be used again for the second turbine. The using of the generator is meant to convert kinetic energy that produced by dual tidal turbines. To convert ocean currents into electrical energy optimally, it is necessary to plan turbine designs that are in accordance with the conditions of ocean currents and the surrounding environment such as current velocity, wind influences and so on. Horizontal-axis tidal turbine (HATTs) is one of the technologies that are being developed and tested in prototype form by several companies, an efficient blade design is very important for the success of the HATTs. The amount of turbine needs, in this case, is 15 turbines with each turbine’s length is 10 meters. The turbines installed in bridge’s column along 800 meters. Estimate electricity can be generated by the turbine is 1.48 Mega Watt (MW).

scholarly journals Forest Fires and Losses Caused by Fires – An Economic Approach

2021 ◽  
Vol 17 ◽  
pp. 181-191
Author(s):  
Beata Sadowska ◽  
Zimon Grzegorz ◽  
Nina Stępnicka
Keyword(s):  
Forest Fires ◽  
Comparative Method ◽  
Research Area ◽  
The State ◽  
European Countries ◽  
Fire Hazards ◽  
Area Of Interest ◽  
Central Statistical ◽  
Central Statistical Office ◽  
Public Forests

A defined forested area performs various functions such as economic, protective and social. Regardless of the level of civilization development and human knowledge, it cannot be stated that humans have full control over the phenomena occurring in forests or their surroundings. Forest hazards, including fire hazards, constitute a direct or indirect factor of human activity that has an effect on nature. Forest fires cause specific losses and generate costs, thus affecting a financial result. The research area of the study is forest fires and losses caused by them, i.e. determining the financial and non-financial effects of fires. The main aim of the study is to present the problem of forest fires in selected European countries, including Poland, and to determine the level of losses caused by them. The research hypothesis is: "Forest fires occurring in European countries, including Poland, cause significant losses in the natural and social environment, which forces organizations to incur costs of implementing measures to protect forest areas against fires". In the case of Poland, the area of interest is public forests managed by the State Forests National Forest Holding. The following research methods were used: critical analysis of the literature, comparative method, desk research, the method of induction and synthesis. In the field of empirical research, the current research results and studies of the Central Statistical Office and the reports of the State Forests were used.

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 If, Why, and When Subjective Well-Being Influences Health, and Future Needed Research

2017 ◽  
Author(s):  
Edward Francis Diener
Keyword(s):  
Well Being ◽  
Research Area ◽  
Cross Cultural ◽  
Subjective Well Being ◽  
Research Issues ◽  
Area Of Interest ◽  
Methodological Approaches ◽  
Open Question ◽  
Do So

We review evidence on whether subjective well-being (SWB) can influence health, why it might do so, and what we know about the conditions where this is more or less likely to occur. This review also explores how various methodological approaches inform the study of the connections between subjective well-being and health and longevity outcomes. Our review of this growing literature indicates areas where data are substantial and where much more research is needed. We conclude that SWB can sometimes influence health, and review a number of reasons why it does so. A key open question is when it does and does not do so – in terms of populations likely to be affected, types of SWB that are most influential (including which might be harmful), and types of health and illnesses that are most likely to be affected. We also describe additional types of research that are now much needed in this burgeoning area of interest, for example, cross-cultural studies, animal research, and experimental interventions designed to raise long-term SWB and assess the effects on physical health. This research area is characterized both by potentially extremely important findings, and also by pivotal research issues and questions.

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.

scholarly journals Hourly Observed Internal Waves by Geostationary Ocean Color Imagery in the East/Japan Sea

2018 ◽  
Vol 35 (3) ◽  
pp. 609-617 ◽  
Author(s):  
Hyuna Kim ◽  
Young Baek Son ◽  
Young-Heon Jo
Keyword(s):  
Internal Waves ◽  
Ocean Color ◽  
Phase Speed ◽  
Japan Sea ◽  
Tidal Energy ◽  
Physical Parameters ◽  
Propagation Behavior ◽  
Wave Heights ◽  
Bottom Shelf ◽  
Ocean Color Imagery

AbstractAs internal waves (IWs) are generated via internal tidal energy near the bottom shelf break of the Korea Strait, continuous evolutions of IWs are extremely difficult to observe using satellite observations. However, the Geostationary Ocean Color Imager (GOCI) has enabled the detection of IWs in the East/Japan Sea (EJS) on an hourly basis to investigate their propagation behavior. For an extended IW analysis, a total of seven packets were identified using GOCI chlorophyll-a concentration (Chl-a) measurements around the Ulleung Basin and Dok Island in the EJS. The results demonstrate that the IW locations had lower Chl-a values than non-IW-affected regions on 10, 11, 13, and 14 August 2013. The lower Chl-a values are due to the significant wave heights of the IWs, which cause surface water masses to be dispersed. In addition, from the continuous trajectories of the waves in the hourly GOCI Chl-a imagery, quantitative physical parameters of the IWs, such as their pathway (northeasterly), phase speed (1.46–1.61 m s−1), amplitude (20.62–26.76 m), and period (12.29 h), could be obtained. Therefore, the advantage of using GOCI is the ability to detect and analyze the physical characteristics of IWs on an hourly time scale.

A brief overview of Materials Science in Uruguay

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3535-3541
Author(s):  
Ivana Aguiar ◽  
Livia Arizaga ◽  
Santiago Botasini ◽  
María Andrea De León ◽  
Sofia Favre ◽  
...  
Keyword(s):  
Materials Science ◽  
Research Area ◽  
Steady State Regime ◽  
Area Of Interest ◽  
Starting Point ◽  
State Regime ◽  
Scopus Database ◽  
Number Of Publications ◽  
Funding Opportunities

ABSTRACTMaterials science is a growing research area in Uruguay. In order to obtain a brief overview of the research done we collected information about research in this field. As a starting point, we searched in the Scopus database for the keywords: affiliation country: “Uruguay” and subject: “Materials Science” (using the “Timbó” platform). We inspected the records and we analyzed them to construct a timeline. The data show that we are in a steady state regime of number of publications that we expect to increase together with the number of students in the area, with the generation of long term policies (grants, funding opportunities), and, if we get involved in a community that promotes this area of interest.

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.

Sign in / Sign up

Export Citation Format

Share Document