• 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.

• Ocean and Polar Research
• /
• 제41권3호
• /
• pp.193-202
• /
• 2019

There have been various approaches for efficiency improvement of a Darrieus tidal stream turbine after it was introduced as an alternative of horizontal axis turbines. Among the approaches, the researches on the interaction effect of dual configuration were conducted. In this study, a dual Darrieus turbine with a coupling mechanism was proposed for investigating the interaction effect. Also, the effect of bi-directional tidal stream was analyzed with prototype fabrication, apparatus set-up and experiment conduction in indoor and offshore facilities. As the results of the experiments, the dual turbine in case of counter-rotation and inflow between the turbines improved efficiencies by 9.5% and 11.31%, respectively, as compared to the single turbine. Also, the dual turbine in case of the inflow improved efficiencies by 9.4% and 16.62%, respectively, as compared to that in case of outflow between the turbines which represented the case of 180 degrees change of flow direction after slack water. Therefore, the proposed dual turbine showed the advantage in terms of the efficiency as compared to the single turbine and the effect level of the slack water on the performance of the dual turbine was investigated.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 추계학술대회
• /
• pp.134-137
• /
• 2006

Tidal power can use conventional technology to extract energy from the tides. It is usually best deployed in areas where there i s a high tical range which includes Western and Southern coastal areas in Korea. However, to extract tical energy, a barrage across an estuary or a bay is to be constructed that is now very hard due to severe environmental impact on local estuary. The recent technology of application of tidal stream provides a new window to extract power minimizing the adverse environmental impact Tidal stream technology which directly exploits these currents is relatively new but is presently generating considerable interest Turbine rotors can be used to extract energy from the flows. Prototype devices currently on test in the UK include the 300kW SeaFlow turbine. In this paper, the recent technology and research on ocean tical stream power are addressed

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.155-162
• /
• 2010

Recently, due to high oil prices and environmental pollution issues, interest of alternative energy development increases and the related research is widely conducted. Among those research activities the tidal stream power generation utilizes the tidal flow as its mechanical power resource and less depends on the environmental condition for installation and operation than other renewable energy resources. Therefore the amount of power generated is quite consistent and straightforward to predict. However, research on the tidal stream energy conversion turbine is rarely found. In the present study, two numerical methods were developed and compared for the open water Momentum Theory, which is widely used for wind turbines, was adopted. The moving reference frame method for Computational Fluid Dynamis solver were also used. Hybrid meshing was used for the complex geometry of turbines. The analysis results using each method were compared to figure out a better method for the performance prediction.

• 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.

• 한국유체기계학회 논문집
• /
• 제17권1호
• /
• pp.47-53
• /
• 2014

This paper aims to present the design and performance evaluation of a counter-rotating tidal turbine using CFD and to compare its performance with single rotor. The device scale is 10kW and the rotating part consists of two rotors which rotate in opposite direction. Compared with conventional single rotor, the counter-rotating system shows higher power efficiency at high stream velocity but lower efficiency at low stream velocity. The added counter-rotated rotor together helps improve the energy absorption capacity but has influence on the upstream rotor that reduces its performance. In terms of power capture, the designed counter-rotating tidal turbine is more advantageous in high speed tidal condition.

• 한국해양환경ㆍ에너지학회지
• /
• 제17권1호
• /
• pp.20-26
• /
• 2014

조류발전 터빈의 효과적인 설계를 위해서는 날개의 변형을 고려한 해석이 필요하다. 날개에 가해지는 유체 하중은 날개 구조를 변형시키고, 터빈의 성능에 영향을 초래한다. 본 연구에서는 수평축 조류발전 터빈의 단독성능을 해석하는 전산유체역학 해석 절차를 개발하였다. 개발한 절차를 이용하여 조류발전 터빈의 성능을 예측하였고 실험결과와 비교하여 검증하였다. 검증된 전산유체역학 방법을 이용하여 복합재 터빈 날개에 대한 유체-구조 연성해석을 수행하였고 강체로 이루어진 터빈 날개에 대한 전산유체역학 해석 결과와 비교하였다.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제1권2호
• /
• pp.64-69
• /
• 2009

The two-dimensional unsteady flow around a vertical axis turbine for tidal stream energy conversion was investigated using a computational fluid dynamics tool solving the Reynolds-Averaged Navier-Stokes equations. The geometry of the turbine blade section was NACA653-018 aiifoil. The computational analysis was done at several different angles of attack and the results were compared with the corresponding experimental data for validation and calibration. Simulations were then carried out for the two-dimensional cross section of a vertical axis turbine. The simulation results demonstrated the usefulness of the method for the typical unsteady flows around vertical axis turbines. The optimum turbine efficiency was achieved for carefully selected combinations of the number of blades and tip speed ratios.

• 한국해양환경ㆍ에너지학회지
• /
• 제13권2호
• /
• pp.105-111
• /
• 2010

조류발전용 HAT 임펠러 설계에 대한 성능 비교 연구를 통하여 설계 개선방향에 대하여 고찰해 보았다. 기존의 조류발전용 임펠러는 풍력에서 사용하고 있는 설계 개념을 그대로 사용하는 경향이 있으며 밀도 차이가 크고 풍력과는 다른 조류발전의 특성을 고려하여 새로이 설계된 임펠러와 기존의 임펠러를 비교하였다. 향후 계산에 의한 비교 뿐 아니라 실험 그리고 경사류등과 같은 특수한 경우에 대한 검증을 수행할 계획이다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
• /
• pp.165.1-165.1
• /
• 2011

In the present study, two numerical methods were developed and compared for the performance prediction of the horizontal axis energy conversion turbine. The Blade Element Momentum Theory was adopted, and the rotating reference frame method for Computational Fluid Dynamics solver was also used. Hybrid meshing was used for the complex geometry of turbines. The analysis results using each method were compared to figure out a better method for the performance prediction.