• 한국해안해양공학회지
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• 제16권4
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• pp.206-212
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• 2004

본 연구에서는 폭이 좁은 1열 및 다열 잠제 대한 파랑 차단 성능을 폭이 넓은 1열 및 2열 잠제의 파랑 차단 성능과 비교$.$연구하였다. 파동장은 선형포텐셜 이론으로 모형화 하였으며 유한요소법을 적용하여 수치해석 하였다. 수치해석 결과, 1열 잠제에서는 폭이 좁은 잠제가 폭이 넓은 잠제보다 파랑 차단 성능이 다소 떨어지나 어느 정도 효과적인 파랑 차단 성능을 보여주고 있으며, 폭이 좁은 잠제를 2열 또는 3열로 배치하였을 때에는 폭이 넓은 1열 또는 2열 잠제보다 훨씬 뛰어난 파랑 차단 성능을 보이고 있다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.453-456
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• 2006

To examine the effect of shape and crest width variation of a permeable submerged breakwater on the wave energy dissipation, Two-Dimensional numerical model with Large Eddy Simulation, which is able to simulate directly WAve Structure Seabed interaction (hereafter, LES-WASS-2D) has been newly developed. A good agreement has been obtained by the comparison between the existing experimental results and LES-WASS-2D model's results for the permeable submerged breakwater. Moreover, based on the LES-WASS-2D model, the wave energy dissipation due to a permeable submerged breakwater are discussed for regular and irregular waves with relation to its crest width and shape.

• 한국항만학회지
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• 제9권2호
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• pp.51-64
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• 1995

Generally, it is pointed out that the submerged breakwater with one row can not regulate the long period waves efficiently, because the crown width is very shorter than the wave length of the long period waves. Therefore, the wide crown is needed to raise the controlling efficiency for the long period waves. This study picks up the submerged breakwater with two rows which has smaller construction materials comparing to the one row and discusses the wave controlling function for the long period waves. Judging from the results obtained by using the strict dividing region method, the submerged breakwater with two rows can more regulate the long period waves than one row can, especially, in case that crown width and inner width of its construction come to be wider.

• 한국해양공학회지
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• 제25권6호
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• pp.29-34
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• 2011

Various types of coastal structures have been constructed to prevent coastal disasters. Among these coastal structures, submerged breakwaters have been used more widely than all of the other coastal structures because of their excellent advantages in scenery effects, construction efficiency, and environmental benefits. This study investigated the potential of the horizontal plate submerged breakwater model. Usually, it is necessary for a submerged breakwater to minimize and compensate for the negative impacts on the marine environment and ecosystem caused by the marine construction. Thus, the prevention of coastal disasters was verified for this submerged breakwater model, regardless of its function as a fish reef. The purpose of this study was to investigate the hydraulic characteristics with changes in the crest width and porosity of a horizontal plate submerged breakwater and compare the results of this study with the results of other studies on permeable and impermeable submerged breakwaters.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 추계학술발표회
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• pp.57-62
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• 2004

선박 조종자는 방파제를 통항할 경우 조선 부담감을 느낀다. 아직까지 선박 운항자의 조선 부담감을 고려한 방파제 배치에 관한 기준은 없다. 이 연구는 해상교통류 시뮬레이션을 이용하여 조선 부담감이 발생하는 상황을 재현하여 선박 운항자의 조선 부담감을 정량적으로 표현한 모델인 환경스트레스모델을 재현된 상황에 적용, 평가하였다. 주요한 결과는 다음과 같다. (1) 방파제 배치 변화에 의한 조선 부담감의 차이는 그다지 크지 않다. (2) 동일한 방파제 폭일 경우에는 선박의 항행속력의 차이로 인하여 선박 운항자의 조선 부담감은 상이하다. (3) 방파제폭의 확장함으로써 선박 운항자의 조선 부담감이 평균적으로 감소한다.

• 대한안전경영과학회지
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• 제11권2호
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• pp.95-101
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• 2009

The present study is to estimate the effect of wave height affecting at the front face of breakwater systems due to specification of submarine trench such as distance from breakwater to dredged area and width of dredge. The wave diffraction field, which is important hydraulic factor in the ocean, is considered to be two dimensional(2D) plane and the configuration of the submarine dredge on the sea bed designated by single horizontal long-rectangular pit system according to the various specific conditions of dredged locations. The numerical simulation is performed by using Green function based on the boundary integral equation and meshed at moving boundary conditions. The results of present numerical simulations are illustrated by applying the normal incidence. It is shown that the ratios of wave height at the front face of breakwater was varied by dependance of distant from breakwater to dredged area and width of dredge. It means that, when the navigation channel or pit breakwater is dredged on seabed, engineers have to consider the specification of dredge. This study can effectively be utilized for safety assessment to various breakwater systems in the ocean field and provided for safety construction of offshore structure.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권2호
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• pp.150-158
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• 2011

Present study aims to investigate the influence of relative breakwater width W/L (W=width of breakwater, L=wavelength), wave steepness $H_i/gT^2$ (Hi=incident wave height, T=wave period) and relative wave height d/W (d=water depth) on forces in the moorings of horizontal interlaced multi-layered moored floating pipe breakwater (HIMMFPB) model. Studies were conducted on scaled down physical models having three layers of Poly Vinyl Chloride (PVC) pipes, wave steepness $H_i/gT^2$ varying from 0.063 to 0.849, relative width W/L varying from 0.4 to 2.65 and relative spacing S/D=2 (S=horizontal centre-to-centre spacing of pipes, D=diameter of pipes). Peak mooring forces were also measured and data collected is analyzed by plotting non-dimensional graphs depicting variation of $f_s/{\gamma}W^2$ ($f_s$=Sea side Mooring force, ${\gamma}$=specific weight of water) & $f_l/{\gamma}W^2$ ($f_l$=Lee side Mooring force) with $H_i/gT^2$ for d/W varying from 0.082 to 0.276 and also variation of $f_s/{\gamma}W^2$ and $f_l/{\gamma}W^2$ with W/L for $H_i$/d varying from 0.06 to 0.400.

• 한국해양공학회지
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• 제21권6호
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• pp.47-52
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• 2007

This paper presents the design of a submerged breakwater, which functions as an eco-structure in a marine environment. Newly patented blocks were used in the submerged breakwater to both make it stable and provide an inhabitable space for fish. To investigate the wave transmission of the proposed submerged breakwater, parametric studies were conducted through two-dimensional hydraulic tests, which were carried out at the National Fisheries Research and Development Institute (NFRDI) in South Korea. Those parameters are relative crest width (B/L), wave steepness (H/L), relative crest depth (hB/H), and submerged breakwater configuration. The hydraulic experimental results can be used to predict the performance of the proposed submerged breakwater covered with the multi-function blocks.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권3호
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• pp.282-291
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• 2017

The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged Navier-Stokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

• Ocean Systems Engineering
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• 제11권1호
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• pp.83-97
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• 2021

The submerged U-shape breakwater interaction with the solitary wave is simulated by the Boussinesq equations using the finite-difference scheme. The wave reflection, transmission, and dissipation (RTD) coefficients are used to investigate the U-shape breakwater's performance for different crest width, Lc1, and indent breakwater height, du. The results show that the submerged breakwater performance for a set of U-shape breakwater with the same cross-section area is related to the length of submerged breakwater crest, Lc1, and the distance between the crests, Lc2 (or the height of du). The breakwater has the maximum performance when the crest length is larger, and at the same time, the distance between them increases. Changing the Lc1 and du of the U-shape breakwaters result in a significant change in the RTD coefficients. Comparison of the U-shape breakwater, having the best performance, with the averaged RTD values shows that the transmission coefficients, Kt, has a better performance of up to 4% in comparison to other breakwaters. Also, the reflection coefficients KR and the diffusion coefficients, Kd shows a better performance of about 30% and 55% on average, respectively. However, the model governing equations are non-dissipative. The non-energy conserving of the transmission and reflection coefficients due to wave and breakwater interaction results in dissipation type contribution. The U-shape breakwater with the best performance is compared with the rectangular breakwater with the same cross-section area to investigate the economic advantages of the U-shape breakwater. The transmission coefficients, Kt, of the U-shape breakwater shows a better performance of 5% higher than the rectangular one. The reflection coefficient, KR, is 60% lower for U-shape in comparison to rectangular one; however, the diffusion coefficients, Kd, of U-shape breakwater is 35% higher than the rectangular breakwater. Therefore, we could say that the U-shape breakwater has a better performance than the rectangular one.