• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.217-225
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• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Ulsan Harbor and Ulsan New Port, etc. due to construction of New Port in Ulsan Bay. This type of trial might be a milestone for port development in macro scale, where the induced impact analysis in the existing port due to the development could be easily neglected.

• Journal of Korean Port Research
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• v.7 no.1
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• pp.79-88
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• 1993

This study deals with the case of a fixed floating structure(FFS) at the mouth of a rectangular harbor under the action of waves represented by the linear wave theory. Modified forms of the mild-slope equation is applied to the propagation of regular wave over constant water depth. The model is extended to include bottom friction and boundary absorption. A hybrid element approximation is used for calculation of linear wave oscillation in and near coastal harbor. Modification of the model was necessary for the FFS. For the conditions tested, the results of laboratory experiments by Ippen and Goda(1963), and Lee (1969) are compared with the calculated one from this model. The cases of flat cylinderical structures, both fixed and floating, were taken to be in an intermediate water depth.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.44-52
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• 2003

항만 및 해안의 이용과 개발 그리고 연안해역공간에서 발생하는 각종 재해를 예방하는 측면에서 볼 때 해안에서 형성되는 여러 물리적인 현상들을 정확하게 이해하고 해석하여 필요에 따라 적절히 활용할 수 있는 것이 무엇보다도 중요한 과제이다. (중략)

• Journal of Navigation and Port Research
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• v.31 no.7
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• pp.579-587
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• 2007

Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.3
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• pp.159-166
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• 2003

In this study, we develop a finite element model to directly solve the Laplace equation while keeping the same computational efficiency as the models based on the extended mild-slope equation which has been widely used for calculation of wave transformation in shallow water. For this, the computational domain is discretized into finite elements with a single layer in the vertical direction. The velocity potential in the element is then expressed in terms of the potentials at the nodes located at water surface, and the Galerkin method is used to construct the numerical model. A common shape function is adopted in horizontal direction, and the cosine hyperbolic function in vertical direction, which describes the vertical behavior of progressive waves. The model was developed for vertical two-dimensional problems. In order to verify the developed model, it is applied to vertical two-dimensional problems of wave reflection and transmission. It is shown that the present finite element model is comparable to the models based on extended mild-slope equations in both computational efficiency and accuracy.

• Journal of Navigation and Port Research
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• v.28 no.5
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• pp.421-428
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• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Pohang Old Harbor and Pohang New Port, etc. due to construction of New Port in Youngil Bay. This type of trial might be a milestone for port development in macroscale, where the induced impact analysis in the existing port due to the development could be easily neglected.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.179-186
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• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Pohang Old Harbor and Pohang New Port, etc. due to construction of New Port in Youngil Bay. This type of trial might be a milestone for port development in macroscale, where the induced impact analysis in the existing port due to the developemnt could be easily neglected.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.3
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• pp.254-261
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• 2001

It is well known that when long waves propagate from deep ocean onto a continental shelf with a very steep continental slope, the waves reflected from the shore can not propagate offshore and are re-reflected from the continental slope so that large water level fluctuations are induced near the shore. Liu(1986) has analyzed this phenomenon by assuming a topography which has a depth discontinuity along a semicircular offshore boundary, but his solution is erroneous. In the present paper, we correct his analytical solutions for a straight shoreline and a rectangular harbor. The corrected solution is then compared with the numerical results of the Galerkin finite element model of Jeong et al.(1998), which is based on the extended mild-slope equation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.53-58
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• 2006

Today, harbor oscillation problems are the most significant factor to consider when designing harbors serving very large ships. In coastal harbors, large vessels moored in the elastic hawsers are often displaced due to the resonance between long period waves and mooring systems. As a result, cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes extreme. The most significant harbor confronted with harbor oscillation problem in Korea is Pohang New port. Many cases of problems are being reported by the pilot association and the local office of MOMAF (Ministry of Maritime Affairs and Fisheries). However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, the Korean government has already started a new port plan at the mouth of Yeongil Bay without addressing the problems that have occurred in Pohang New port. This study deals with the variation of harbor oscillation due to the construction of a 4.1 km breakwater at the bay mouth including the arrangement of the new berths. Numerical methods used are in fairly standard form from the extended mile slope equation. The obtained numerical results were compared with field measurement from the previous and this will bring a certain level of discussion and consideration of variation to the future port development.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.127-135
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• 2009

Reid and Kajiura(1957) has studied on the wave damping rate over a permeable bed of infinite depth. In this study, wave damping rate over a permeable bed of finite depth is derived by linear wave theory. It is then extended to derive wave damping rates over a double or triple layer, each of which consist of different material. Applying the wave damping rate to the mild slope equation, the wave transmission coefficient over a permeable bed has been calculated. The model has been certificated by comparing with the result of Flaten and Rygg(1991)'s integral equation method in the case of a single-layer bed.