• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.357-359
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• 2007

해양에너지원 중에서 파랑은 모든 해역에 폭넓게 분포하므로 가용에너지원이 풍부하고 에너지를 회수하기 위한 장치를 설치할 수 있는 해역 또한 광범위하며 반도의 지형을 지닌 우리나라의 연안 해역에 대규모로 활용이 가능한 에너지 자원중 하나이다. 본 연구는 새로운 방식인 파력발전용 횡류형터빈인 케이슨 내장형 횡류터빈을 개발하기에 앞서 파랑수조의 왕복운동을 CFD해석을 통하여 구현하는 것이다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.2
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• pp.154-165
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• 2006

In the present study, a numerical model using Boussinesq equation is set up to predict the interacted equilibrium between waves and their induced currents in the occurrence of breaking waves over an underwater shoal, and the numerical results are compared with results of existing hydraulic experiments. A sensitivity analysis has been done to find out appropriate values of breaking wave parameters with the result (regular wave case) of Vincent and Briggs (1989)’ experiment. Then the numerical model is applied to the irregular wave cases of the experiment and the hydraulic model test of Ieodo which is a natural undersea shoal. The results show that a strong current forms in the wave direction at the downstream side of the shoals, causing the attenuation of wave heights there. The calculated wave heights generally show a similar pattern with the measured data.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1997.10a
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• pp.63-67
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• 1997

파랑이 탁월한 영역에 존재하는 중소어항의 대부분을 항내매몰이 중요문제 중의 하나로서, 입ㆍ출항의 곤란 및 반복되는 준설경비의 소요 등으로 경제적 문제를 겪고있다. 따라서 이와 같은 문제를 장기적으로 해결하기 위해서는 항내매몰의 근본적 원인을 빠른 시일 내에 정확히 파악하고, 그 대책공법을 강구할 필요가 있다. 본 연구는 이러한 문제를 해결하기 위해 파랑 및 연안류제어 구조물의 설치 및 배치 등을 이용한 항내매몰 방지대책을 설정하여 각각의 연안류 및 해빈변형제어효과를 검토하고 항내매몰에 미치는 영향을 검토해 보았다. (중략)

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.65-71
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• 1991

Many investigations of wave deformation without currents have been carried out experimentally and theoretically but, studies treating the effect of longshore current on the wave deformation are few. It is thus necessary to evaluate the effect of longshore current on the wave deformation after breaking. In the paper the wave height attenuation. the wave direction and the variation of mean water level are calculated in which effects of longshore current are involved. To assess the effect of longshore current on the wave deformation, factors above with longshore current are compared with them without longshore current by using calculated results.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.62-65
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• 2002

파랑은 주로 먼바다에서 바람에 의해 생성되어 육지로 전파해오면서 천수, 굴절, 회절, 반사, 부서 짐 등의 여러 가지 변형의 과정을 거친다. 이러한 파랑의 변형을 예측하는 한 방법은 비압축성 유체와 비회전류의 연속방정식인 Laplace 방정식을 지배 방정식으로 하고 해수면에서의 운동학적 경계조건과 동역학적 경계 조건, 그리고 바닥에서의 운동학적 경계조건을 적용하여 해를 구한다. (중략)

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.4
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• pp.308-315
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• 2009

Wave-current interaction due to strong ambient currents causes to alter wave properties such as wave height, wave profile and wave spectrum. In this study we first examined the SWAN model's applicability by comparing with an analytical solution of Suh et al. (1994) for wave-current interaction in finite water-depth. Numerical experiments using SWAN model have been conducted for Garolim Bay to estimate the design waveheights influenced by strong tidal currents. For the design wave periods of 8~10 sec, the design wave height of 3 m in NNW direction was increased by up to 40% when the incident waves encounter the opposing currents of 1.4 m/s while the wave height was reduced by 26% due to the following currents of 1.1 m at the bay mouth. This result indicates that the effect of wave-current interaction must be included to determine the design wave height if there exists a strong current.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.1
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• pp.54-64
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• 1991

To accurately estimate the rate of sediment transport in shallow water bodies, it is necessary to investigate the irregular waves transformation characteristics and nearshore currents produced by random sea waves. Most of studies on numerical models for nearshore currents are based on the theory of monocromatic waves and thus, very few nearshore models take into account the effect of irregularities in the hight, period and directional spreading of incident waves. The numerical simulation model for nearshore currents used in this paper considers the effect of irregularities of incident waves, based on Individual Wave Analysis. The computational results are compared and shown in a reasionable agreement with the experimental data.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.173-179
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• 2013

The interaction among wave, seabed and marine structure is an important issue in coastal engineering as well as geotechnical engineering. Understanding variations of stresses and pore water pressures generated in seabed induced by waves is important for civil engineers who have to design the foundation for various marine structures and verify the instability of seabed. In the matters on seabed instability, particularly, in the case of wave-induced liquefaction of seabed, it is turned out there are two different mechanisms through previous studies. These are caused by the transient or oscillatory nature and the residual or progressive nature of excess pore water pressure generated in seabed, respectively. In this study, it is analyzed dynamic characteristics of soils sampled in seabed around the port of Kochi, Japan, through the dynamic triaxial tests and the residual excess pore water pressure in the seabed induced by seepage force of wave. In addition, the calculated residual excess pore water pressures were compared with the field data observed in the port of Kochi.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.350-362
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• 2017

The Eulerian nearshore current model is more advantageous than the Lagrangian model in the way that numerical results from the Eulerian model can be directly compared with the measurements by the stationary equipment. It is because the wave mass flux is not included in the computed mass flux of Euleran nearshore current model. In addition, the Eulerian model can simulate the longshore currents with depth varying parabolic profile. However, the numerical models proposed by different researcher have different forms of the wave stress terms. For example, wave stresses in Newberger and Allen's (2007) model is constant over the depth, while those of Chun (2012) are vertically distributed. In the present study, these wave stress terms were compared against Hamilton et al.'s (2001) laboratory experiments to see the effects of different wave stress terms performed on the computation of nearshore currents.

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.693-706
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• 2011

The Geomorphological properties and ages of river-mouth bar at Song-cheon River in the East Coast of Korea, Yeongdeok-gun, Gyeongbuk Province are estimated, and the long-term and short-term changing processes and causes are analyzed. Sand grains of the bar near the coastline show the finer trends from south to north and these can be attributed to the northward movement of waves and long-shore currents. The absolute ages of bar and nearby coastal sand dune are less than approximately 100 years ago, indicating that the bar has experienced the active geomorphological changes. While the inlet located at south part of the bar between 1971 and 1995, the inlet has located at north or middle part since 1995. These may caused by the changes of movement directions of waves and long-shore currents due to the apparent northward movements of winds and currents. In short-term, the higher elevation, larger area, simpler landform relief and more variable location of inlet and morphology of bar can be observed between September and March due to the dominance of sedimentary processes by wave and wind processes.