• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
• /
• pp.309-309
• /
• 2011

This paper outlines extraction potential of tidal stream resources from the simplified channel in which flow is driven by a head difference between inlet and outlet. Energy extraction alters the flow within a simple channel, and extraction of 10% energy flux in a natural channel would give rise to a flow speed reduction of about 5.7%.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
• /
• pp.79-79
• /
• 2011

The oceans are an untapped resource, capable of making a major contribution to our future energy needs. In the search for a non polluting renewable energy source, there is a push to find an economical way to harness energy from the ocean. Tidal stream is one of ocean energy form that is being investigated as potential source for power generation. Tidal current turbines are therefore designed as conversion machinery to generate power from tidal currents. A study on energy extraction from tidal currents is presented in this paper.

• 한국유체기계학회 논문집
• /
• 제19권4호
• /
• pp.54-62
• /
• 2016

This study presents an approach of tidal farming optimization using a numerical modelling method to simulate tidal energy extraction for 1MW scale tidal stream devices around Jangjuk-sudo, South Korea. The utility of the approach in this research is demonstrated by optimizing the tidal farm in an idealized scenario and a more realistic case with three scenarios of 28-turbine centered tidal array (named A, B and C layouts) inside the Jangjuk-sudo. In addition, the numerical method also provides a pre-processing calculation helps the researchers to quickly determine where the best resource site is located when considering the position of the tidal stream turbine farm. From the simulation results, it is clearly seen that the net energy (or wake energy yield which includes the impacts of wake effects on power generation) extracted from the layout A is virtually equal to the estimates of speed-up energy yield (or the gross energy which is the sum of energy yield of each turbine without wake effects), up to 30.3 GWh/year.

• 해양환경안전학회지
• /
• 제17권1호
• /
• pp.23-28
• /
• 2011

조류자원을 평가하기 위해 양쪽이 무한한 바다에 연결되어 있고, 수평한 바닥을 갖고 있는 수로를 가정하고, 수위의 시간변화에 따른 동적효과를 무시한 개수로 유동에서 양 끝단의 수두 차에 의해 구동되는 단순 수로에 대해 에너지 추출 모델을 제안하였다. 조류에너지는 그 단면을 지나는 유속의 3승에 비례하며, 수로 내에서의 에너지 추출은 반드시 유속의 감소를 초래하였다. 교란되지 않는 흐름의 수로에서 10%의 에너지 추출은 약 5.7%의 유속 감속을 초래하며, 20%가 추출되면 유속은 약 11.3%로 감소되었다. 또한, 수로 내에서 더 유속 감소가 가능하다면 이용 가능한 에너지의 추출은 보다 높을 수 있음을 보였다.

• Ocean Systems Engineering
• /
• 제13권3호
• /
• pp.247-268
• /
• 2023

Tidal stream energy extraction remains a site-specific resource due to the "first generation" criteria requiring high-velocity tidal streams. Most studies on tidal energy and turbine blade design heavily focus on installation sites with higher velocity conditions that are non-existent in tropical countries such as the Philippines. To shorten this gap, this review paper tackles tidal turbine design considerations for low-energetic regions such as the tropics. In-depth discussions of operating principles, methods of analysis, and designs of tidal turbine blades are presented. Notable tidal stream projects around the world are also mentioned in the paper. Also, it provides a perspective on the potential of this renewable energy to produce electricity for various sites in the Philippines. Finally, the paper emphasizes the need for new tidal turbine blade designs to be viable in tropical regions, such as the Philippines.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
• /
• pp.247-249
• /
• 2006

The objective of this study is to detect a inter-tidal topographic change in a decade. Waterline extraction is a one of widely used method to generate digital elevation model (DEM) of tidal flat using multi-temporal optical data. This method has been well known that it is possible to construct detailed topographic relief of tidal flat using waterlines In this study, we generated two sets of tidal flat DEM for the southern Ganghwado. The DEMs showed that the Yeongjongdo northern tidal flat is relatively high elevation with steep gradients. The Ganghwado southern tidal flat is relatively low elevation and gentle gradients. To detect the morphologic change of tidal flat during a decade, we compared between early 1990's DEM and early 2000's DEM. Erosion during a decade is dominant at the west of southern Ganghwado tidal flat, while sedimentation is dominant at the wide channel between the southern Ganghwado and Yeongjongdo tidal flats. This area has been commonly affected by high current and sedimentation energy. Although we are not able to verify the accuracy of the changes in topography and absolute volume of sediments, this result shows that DEM using waterline extraction method is an effective tool for long term topographic change estimation.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.22-24
• /
• 2007

Waterline extraction is the one of widely used methods for studying changes in tidal flat environment and coastlines using multi-temporal optical images such as Landsat TM and Landsat ETM+. High dynamics of tidal currents and land reclamation which accelerate sedimentation and/or erosion cause waterline change in tidal flats. The amount of sediment deposited or eroded can be evaluated by precisely estimating waterline changes in tidal flats. The objective of this study is to detect the change of waterlines during 17 years and analyze the trends of erosion and sedimentation in the study areas. The Ganghwado tidal flat on the west coast of the Korean Peninsula was selected. The study area is famous for high dynamics of tidal currents and vast tidal flats. Land reclamation which has been carried out on a large scale is also considered as one of elements that have accelerated the environmental changes in this tidal flat. In this study, we acquired 26 waterlines from Landsat TM and Landsat ETM+ images. We extracted the waterline from each satellite image to generate a digital elevation map (DEM) which was used for reference and to compare with the other waterline which was extracted from DEM having a same tide. The result of comparison well depicted the areas of dominant sedimentation and erosion, and general trends of sedimentation and erosion according to sub-regions are also revealed during the investigation time. Results showed that erosion during a decade was dominant at the west of the Southern Ganghwado tidal flat, while sedimentation was dominant at the wide channel between the Southern Ganghwado tidal flat and the Yeongjongdo tidal flat. This area has been commonly affected by high currents and sedimentation energy. Although we were not able to verify the accuracy of the waterline changes, this result clearly showed the waterline change and therefore, the waterline extraction method used in this study has proven as an effective tool for long term tidal change estimation.

• 해양환경안전학회지
• /
• 제25권7호
• /
• pp.982-990
• /
• 2019

최근 점점 더 많은 연구자와 정부에서 해양에너지 자원 개발에 대한 관심이 고조되고 있다. 장죽수도는 조류에너지 밀도가 높아 조류 발전소를 건설하기에 적합한 잠재적 후보지 중 하나이다. 따라서 본 연구에서는 ADCIRC 모델을 이용하여 장죽수도의 조류자원의 잠재량을 평가하기 위한 수치적 접근방식을 제시하고, 내부 코드를 이용하여 조석 특성을 입력 매개변수로 활용하여 1 MW급 규모의 조류에너지 변환장치를 대상으로 4개의 레이아웃으로 배열하고 후류 효과로 인한 연간 에너지 생산량에 관한 수치해석을 수행하였다. 그 결과 효율이 가장 좋은 배치는 연간 최대 12.96 GWh/year의 에너지를 생성할 수 있으며, 이 값은 후류 효과로 인한 에너지 손실을 고려하면 연간 0.16 GWh씩 감소될 수 있음을 보였다. 또한, 창낙조 때 터빈 요 각도를 변경함으로써 이 요소가 에너지 추출에 미치는 영향을 분석하였으며, 터빈 배열은 터빈 요 각도가 346°와 164°(북쪽에서 시계 방향으로)일 때 대조기와 소조기에서 차례로 최대 조류 에너지를 얻을 수 있었다.

• International Journal of Fluid Machinery and Systems
• /
• 제1권1호
• /
• pp.33-37
• /
• 2008

EquiMar (Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact) is one of the first round of energy projects under the European Commissions 7th Framework Programme (FP7). The three year EquiMar project aims to deliver a suite of protocols for the evaluation of both wave and tidal converters, harmonizing testing and evaluation procedures across the wide range of available devices, accelerating adoption through technology matching and improving the understanding of both environmental and economic impacts associated with the deployment of devices. The EquiMar protocols will cover site selection, initial design, scaling up of designs, the deployment of arrays and environmental impact assessment as well as economic issues. EquiMar will build on existing protocols, e.g. UK DTI Marine Renewables Development Fund (MRDF) protocols for wave and tidal energy, and engage with international standards setting activities, e.g. IEC TC114.

• 한국유체기계학회 논문집
• /
• 제18권1호
• /
• pp.51-58
• /
• 2015

This paper presents a study on Vane Tidal Turbine (VTT) focusing on analysis of two types of blade arrangement originated from the previous studies where the original design was examined and performance-tested for different numbers of blades (six, eight and twelve). Compared to conventional tidal turbines, VTT has several special features and potential advantages which have been being thoroughly developed. The purpose of this study is to analyze VTT's capability of extracting and converting the hydrokinetic energy of tidal currents into electricity at given arrangement of blades (single and double rows, six and twelve blades) using CFD. From the calculation results, the six-blade single row turbine shows the best performance, in which the highest power and torque coefficients reach up to about 34 % and 36 %, respectively, at TSR=0.94. However, despite of lower power coefficient, by adding more blades, the torque's extraction of twelve-blade turbine, especially the double row type, is less fluctuate than that of the six-blade setups.