• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.249-253
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• 2003

심해로부터 해안으로 전파해오는 파랑은 해저지형 또는 구조물 등의 영향을 받아 반사, 쇄파 등과 같은 변형을 겪게 되며, 이와 같은 파랑은 연안침식 및 해안구조물의 안전과 설계에 영향을 미친다. 수중방파제(submerged breakwater)는 입사하는 파랑에너지를 대규모로 감소시켜 연안침식을 방지할 뿐만 아니라 방파제를 수중에 건설함으로써 해역환경의 개선을 가능하게 한다. 또한, Bragg반사를 이용하여 수중방파제를 건설할 경우, 연안의 불필요한 침식 및 퇴적현상을 최소화할 수 있을 뿐만 아니라 입사파에 의해 발생하는 해안구조물의 손상을 사전에 방지 할 수 있다. 아울러, 항만의 정온도를 향상시키는데 효과적으로 이용할 수 있다. (중략)

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.87.2-87.2
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• 2009

• Journal of Korea Water Resources Association
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• v.36 no.5
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• pp.741-749
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• 2003

This study presents a combined experimental and numerical effort to investigate experimentally and numerically the Bragg reflection of sinusoidal waves due to trapezoidal submerged porous breakwaters. Numerical predictions of the study are verified by comparing to laboratory measurements. In the numerical model, the flow in porous structures is described by the spatially averaged Navier-Stokes equations and the volume of fluid method is employed to track the free surface displacements. Numerical solutions are agree well with laboratory measurements. The reflection coefficients of porous structures are smaller than those of non-porous structures and become stronger in proportion to the increase of number of submerged breakwaters.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.447-454
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• 2003

The Bragg reflection of monochromatic waves propagating over a rectangular-typed impermeable submerged breakwaters is numerically investigated by using the finite element method. The reflection coefficients calculated from the present model are compared with those of laboratory measurements and the eigenfunction expansion method. A good agreement is observed. The finite element model is also applied to calculate reflection coefficients according to variations of length and width of submerged breakwater.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.1
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• pp.29-37
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• 2007

In this study, transmission and reflection of multi-directional random waves propagating over impermeable submerged breakwaters are calculated by using eigenfunction expansion method. A series of mutiderectional random waves is generated by using the Bretschneider-Mitsuyasu frequency and Mitsuyasu type directional spectrum. Strong reflection is occurred at the Bragg reflection condition of the peak frequency. If the row of breakwaters is fixed at 3 and the relative height of breakwater is fixed at 0.6, more than 25% of incident wave energy is reflected to offshore. It is also found that the reflection of directionally spreading random waves increases as the maximum spreading parameter $s_{max}$ increases.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.413-420
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• 2006

The construction of a submerged breakwater has become increasing due to their multiple effects on the coastal zone. Recently, marker rocks have been installed on the submerged breakwater to indicate its position to the vessels instead of buoy systems, since a buoy is not only improper for the ocean view, but also its mooring system may be damaged by the impulsive wave force caused by wave breaking on the breakwater. The accurate estimation of wave forces on such rocks is deemed necessary for their stability design. In this study, the characteristics of irregular wave forces acting on a marker rock, which was installed on a submerged breakwater, was investigated on the basis of laboratory experiments. It was revealed that the dimensionless highest one-third wave force tends to decrease with increasing the installation distance of a marker rock from the leading crown edge of a submerged breakwater. Also, the drag and inertia coefficients for irregular wave forces, which were obtained using the Morison equation, were investigated in relation to K.C. number.

• Journal of Korea Water Resources Association
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• v.35 no.5
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• pp.563-573
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• 2002

In this study, reflection of water waves over a train of rectangular submerged breakwaters is experimentally investigated. Measured reflection coefficients of regular waves are compared with predicted coefficients obtained from the eigenfunction expansion method. Although measured coefficients are slightly smaller than predicted ones, the overall agreement is very good.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.2094-2097
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• 2007

본 연구에서는 사석경사제의 전면부에 불투과성 수중방파제를 설치하여, 불규칙파의 반사에 대한 수치모의와 수리모형실험을 수행하였다. 수치해석 모형에는 Reynolds Averaged Navier-stokes (RANS) 방정식을 지배방정식으로 사용하였고, 난류해석을 위하여 $\kappa-\varepsilon$ 방정식을 사용하였다. 자유수면변위의 정확한 예측을 위하여 VOF 기법을 적용하였다. 수리모형실험은 한양대학교 수리실험실의 조파수로에서 수행되었다. 본 연구에서는 입사파랑으로 불규칙파를 조파하였으며, Bretsch neider-Mistuyasu 스펙트럼을 목표스펙트럼으로 하여 재현하였다. 반사율의 산정에서 입사파와 반사파를 분리하기 위하여 수치모형실험에서는 3점법을 사용하였고, 수리모형실험에서는 2점법을 사용하였다. 수치모의를 통하여 예측된 반사율과 수리모형실험에서 관측한 결과는 서로 잘 일치하였다.

• Journal of Korea Water Resources Association
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• v.37 no.11
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• pp.949-958
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• 2004

A combined experimental and numerical effort is presented for investigation of reflection of irregular waves due to rectangular submerged breakwaters. In the numerical model, the Reynolds equations are solved by a finite difference method and k-$\varepsilon$ model is employed for the turbulence analysis. To track the free surface displacement, the volume of fluid method is employed. Numerical predictions of transmission and reflection coefficients are verified by comparing to laboratory measurements. Very reasonable agreements are observed. The reflection coefficients become stronger in proportion to numbers of submerged breakwaters.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.214-216
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• 2018

강원도 정동진해변은 이상시 고파랑에 의한 연안침식피해가 상시 발생하고 있기 때문에 이에 대한 해안복원을 위하여, 정밀 조사, 실험을 통해 연안침식원인을 분석하고 해안 안정을 위한 근본적인 대책을 수립하였으며, 자연재해로 인한 연안침식 예방과 연안시설에 대한 지속적인 유지관리로 연안환경을 보전하고자 하였다. 이를 위하여 수중방파제, 돌제, 양빈 등의 대책을 마련하였으며, 제언하여 이후 퇴적환경 모니터링을 지속화 시킬 필요가 있을 것으로 판단된다.