• 한국해안·해양공학회논문집
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• 제27권1호
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• pp.50-55
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• 2015

본 연구에서는 등부표를 이용하여 외해에서 입사되는 파랑에너지를 전기에너지로 변환시키는 파력발전 방식에 대하여 연구하였다. 등부표와 직선형과 시소형 자가 발전체를 1/10 축소 모형으로 제작하고, 파랑수조에서 실험을 실시하였다. 이러한 시스템에서 서로 다른 파고와 주기를 갖는 파랑을 대상으로 등부표의 수평 및 수직 경사, 발생 전류와 에너지를 측정하였다. 이를 통하여 전기 에너지 획득 가능성을 확인하였고, 차후 연구 과제를 제안하였다.

• Wind and Structures
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• 제22권1호
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• pp.107-131
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• 2016

The need for a more affordable, reliable, clean and secure energy has led to explorations in non-traditional sources, particularly renewable energies. Wind is one of the cleanest energy sources that plays a significant role in augmenting sustainability. Wind turbines, as energy convertors, are usually tall and slender structures, and depending on their location (inland or offshore), they can be subject to high wind and/or strong wave loadings. These loads can cause severe vibrations with detrimental effects on energy production, structural lifecycle and initial cost. A dissipativity analysis study was carried out to know whether wind turbine towers require damping enhancement or rigidity modifications for vibration suppression. The results suggest that wind turbines are lightly damped structures and damping enhancement is a potential solution for vibration lessening. Accordingly, the paper investigates different damping enhancement techniques for vibration mitigation. The efficacy of tuned mass damper (TMD), tuned liquid column damper (TLCD), tuned sloshing damper (TSD), and viscous damper (VD) to reduce vibrations is investigated. A comparison among these devices, in terms of robustness and effectiveness, is conducted. The VD can reduce both displacement and acceleration responses of the tower, better than other types of dampers, for the same control effort, followed by TMD, TSD, and finally TLCD. Nevertheless, the use of VDs raises concerns about where they should be located in the structure, and their application may require additional design considerations.