• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.118-120
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• 1992

천해역에 있어서의 다방향불규칙 파랑장의 특성을 조사하는 하나의 중요한 수법으로서 파별해석법에 의해 정의 되어진 개개파 통계적 해석법이 있다. 파별해석 되어진 개개파에 대한 역학적 근거는 반드시, 명확하지 않지만 파별해석할 경우 개개파의 파고, 주기, 파향을 어떻게 정의 해야 할 것이라는 것은 매우 중요한 과제이다.(중략)

• Journal of Wetlands Research
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• v.18 no.1
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• pp.84-93
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• 2016

As a transition region between ocean and land, coastal wetlands are significant ecosystems that maintain water quality, provide natural habitat for a variety of species, and slow down erosion. The energy of coastal waves and storm surges are reduced by vegetation cover, which also helps to maintain wetlands through increased sediment deposition. Wave attenuation by vegetation is a highly dynamic process and its quantification is important for understanding shore protection and modeling coastal hydrodynamics. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type as well as wave conditions. Wave attenuation characteristics were investigated under regular waves for rigid model vegetation. Laboratory hydraulic test and numerical analysis were conducted to investigate regular wave attenuation through emergent vegetation with wave steepness ak and relative water depth kh. The normalized wave attenuation was analyzed to the decay equation of Dalrymple et al.(1984) to determine the vegetation transmission coefficients, damping factor and drag coefficients. It was found that drag coefficient was better correlated to Keulegan-Carpenter number than Reynolds number and that the damping increased as wave steepness increased.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.1 no.1
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• pp.63-70
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• 1989

A numerical analysis of the wave characteristics of wave diffraction and the interference effects for a single cylinder and for two cylinders were carried out by the Boundary Element Method using constant elements. The Present investigation was limited to the diffraction of 2-dimensional linear waves by vertical impervious cylinders. Numerical model has been written to calculate the wave diffraction coefficient both on the boundary of the cylinders and at points away from it. The accuracy of the computational scheme was investigated by comparing the analytical results of the other reseraches. Good agreement was observed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.3
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• pp.195-201
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• 2001

The time simulation of slow drift motions of moored FPSO in waves is presented. The equation of motion based on Cummin's theory of impulse responses are employed, and are consisted of horizontal plane motions such as surge, sway and yaw. The added mass, wave damping coefficients, first order wave exciting forces and the second order wave drift forces involved in the equations are obtained from three-dimensional panel method in the frequency domain. The mooring lines are modeled as quasi-static catenary cable. As a numerical example, time domain analyses are carried out for a box-type FPSO in long crest irregular wave condition.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.175-180
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• 2012

The shape of floating superstructure is the same as other buildings, but the foundation is based not on land but on a floating body. Unlike inland structures, they are largely influenced by the wave load. Deformation of the floating pontoon due to the wave loads affects the connection, which in turn causes problems related to the habitability and safety to the superstructure users. Accordingly, this study conducted elastic analysis regarding rigid connection and semi-rigid connection by the integration analysis that combined together the superstructure and pontoon of the 3-D floating structure. Moreover, this study investigated the results of the separation analysis excluding pontoon and the integration analysis. In addition, elasticity analysis was used to divide up the wave loads cases, and to classify the moment and displacement of the structure depending on connection following the changes in the wave loads.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.203-216
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• 2021

Analyzing various wave interactions with oscillating wave surge converters (OWSC) is essential because they must be operated efficiently under a wide range of wave conditions and designed to extract optimal wave energy. In the conceptual design and development stage of OWSC, numerical analysis can be a good alternative as a design tool. This study performed a numerical analysis on the behavioral characteristics of the inverted triangle flap against the incident waves using open source CFD to examine the essential behavioral attributes of OWSC. Specifically, the behavioral characteristics of the structure were studied by calculating the free water surface displacement and the flap rotation angle near the inverted triangular flap according to the change of the period under the regular wave conditions. By comparing and examining the numerical analysis results with the hydraulic model experiments, the validity of the analysis performed and the applicability in analyzing the wave-structure interactions related to OWSC was verified. The numerical analysis result confirmed that the hydrodynamic behavior characteristic due to the interactions of the wave and the inverted triangle flap was well reproduced.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.128-130
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• 2011

플로팅 구조물은 파랑하중의 영향에 따라 함체가 변형하게 되며, 이러한 변형이 상부구조물에 영향을 주게 된다. 함체의 강성변화 및 파랑의 주기변화에 따라 해석을 수행한 결과 함체의 강성이 증가할수록 모멘트는 감소하며, 축력에 대한 영향은 미미하다. 함체의 강성이 같다면 파랑의 주기가 길어질수록 모멘트는 증가한다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2000.09a
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• pp.149-154
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• 2000

파랑은 먼바다에서 주로 바람에 의하여 생성되어 천해로 전파되어 오면서 천수, 굴절, 회절, 반사, 중첩의 여러 가지 변형 과정을 거친다. 이 변형 과정 가운데 바닥의 영향으로 발생하는 것은 천수, 굴절, 반사이고 파랑간에 발생하는 것은 회절, 중첩이다. 수심이 파장의 1/2보다 작은 경우 바닥의 영향을 받게 되는데 이 해역이 중간수심해와 천해에 해당한다. 파랑변형모형은 파향선추적법부터 시작된다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.137-141
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• 1993

최근 천해역에서의 파랑의 변화양상에대한 많은 연구가 수행되어 괄목할만한 진전을 보였으나 그 연구범위가 단일한 형태의 파랑을 대상으로한 확정론적인 접근방법에 치우쳐 있었다. 그러나 해수면의 상당 부분은 언제나 불규칙한 파랑에 의해 점유되어 있다. 이러한 불규칙성은 바람의 mechanical energy가 해수면으로 전이되는 과정에 기인하는 데 ［Phillips, 1980］ 따라서 파랑장의 해석에는 통계적인 방법이 이용되곤한다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.26-28
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• 1993

해안구조물의 설치나 해안환경 문제를 다룰때 가장 필수적인 것이 그 지역에서의 정확한 파랑자료이다. 파랑은 천해로 전파해 옴에 따라 수심 및 지형변화로 인한 회절 및 굴절을 겪으면서 변하게 되므로 복잡한 지형을 가진 해안에서의 정확한 파랑계산은 용이한 일이 아니다. 이러한 파랑변형에 대한 연구는 Berkhoff(1972)가 완경사방정식을 발표한 후 큰 진전을 보이게되는데 이로 인해 종래 개별적으로 다루던 굴절과 회절을 함께 취급할 수 있게 되고 파향선이 교차할때 생기는 불합리한 에너지의 집중(caustics)을 해결할 수 있게 되었다. (중략)