• Journal of Ocean Engineering and Technology
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• v.21 no.2 s.75
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• pp.35-41
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• 2007

In general, coastal damage is mostly occurred by the action of complex factors, like severe water waves. If the maximum storm surge height combines with high tide, severe water waves will overflow coastal structures. Consequently, it can be the cause of lost lives and severe property damage. In this study, using the numerical model, the storm surge was simulated to examine its fluctuation characteristics at the coast in front of Noksan industrial complex, Korea. Moreover, the shallow water wave is estimated by applying wind field, design water level considering storm surge height for typhoon Maemi to SWAN model. Under the condition of shallow water wave, obtained by the SWAN model, the wave overtopping rate for the dike in front of Noksan industrial complex is calculated a hydraulic model test. Finally, based on the calculated wave-overtopping rate, the inundation regime for Noksan industrial complex was predicted. And, numerically predicted inundation regimes and depths are compared with results in a field survey, and the results agree fairly well. Therefore, the inundation modelthis study is a useful tool for predicting inundation regime, due to the coastal flood of severe water wave.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.3
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• pp.166-178
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• 2012

In order to simulate storm surge for the west coast, complex physics of asymmetrical typhoon wind vortex, tide and wave are simultaneously incorporated on a fine finite element mesh extended to the North Western Pacific sea. Asymmetrical vortex based on maximum wind radii for each quadrant by JTWC's best tracks are input in pADCIRC and wave stress is accounted by dynamic coupling with unSWAN. Computations performed on parallel clusters. In hindcasting simulation of typhoon Kompasu(1007), model results of wave characteristic are very close with the observed data at Ieo island, and sea surface records at major tidal stations are reproduced with satisfaction when typhoon is approaching to the coast. It is obvious that increasing of local storm surges can be found by introducing asymmetrical vortex. Thus this approach can be satisfactorily applied in coastal hazard management against to storm surge inundation on low level area and major harbor facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.77-83
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• 1986

In this paper, an accurate model for structural analysis of frames with shear walls is introduced. Static and dynamic analysis of two example structures has been performed using the computer program SWAN which employes the newly developed 12 degrees of freedom plane stress element and the results are compared to those obtained using SAP IV. The 12 degrees of freedom element resulted in improved shear stress distribution in wall elements and bending moment in beam elements.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.177-180
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• 2018

As ships operating on the Arctic route are exposed to various ice environments such as level ice, pre-swan, pack ice, ice ridge and brash ice, it is essential to estimate the ice resistance according to the ice environment. Methods for estimating the ice resistance include a method using mathematical model, numerical simulation, and a method using empirical formula. In this study, empirical formulas are used to estimate the ice resistance. The purpose of this study is to develop the ice resistance and attainable speed estimation program(I-RES) for various ice environments.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.35 no.4
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• pp.67-74
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• 2023

High waves and storm surges due to tropical cyclones cause great damage in coastal areas; therefore, accurately predicting storm surges and high waves before a typhoon strike is crucial. Meteorological forcing is an important factor for predicting these catastrophic events. This study presents an improved methodology for determining accurate meteorological forcing. Typhoon Chaba, which caused serious damage to the south coast of South Korea in 2016, was selected as a case study. In this study, symmetric and asymmetric parametric vortex models based on the typhoon track forecasted by the Model for Prediction Across Scales (MPAS) were used to create meteorological forcing and were compared with those models based on the best track. The meteorological fields were also created by blending the meteorological field from the symmetric / asymmetric parametric vortex models based on the MPAS-forecasted typhoon track and the meteorological field generated by the forecasting model (MPAS). This meteorological forcing data was then used given to two-way coupled tide-surge-wave models: Advanced CIRCulation (ADCIRC) and Simulating Waves Nearshore (SWAN). The modeled storm surges and waves correlated well with the observations and were comparable to those predicted using the best track. Based on our analysis, we propose using the parametric model with the MPAS-forecasted track, the meteorological field from the same forecasting model, and blending them to improve storm surge and wave prediction.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.29-35
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• 2011

In order to effectively control waves in a coastal zone, Multi-Cylinder Piles have been suggested as economic structures. A numerical analysis was conducted using the Delft-3D: WAVE module based on SWAN, which considered wave shoaling and refraction. Moreover, irregular waves were used to investigate the hydrodynamic characteristics of the wave interaction with the structure. In this paper, a numerical analysis was carried out to research the effect of wave control through a wave height analysis concerning an existing, concrete wave breaker and multi-cylinder piles placed at the same location. As a result, the effect of the wave control is shown using the wave breaker, multi-cylinder piles, and existing data.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.103-115
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• 2018

This paper performs a numerical computation of ship maneuvering performance in waves. For this purpose, modular-type model (MMG (Mathematical Modeling Group) model) is adopted for maneuvering simulation and wave drift force is included in the equation of maneuvering motion. In order to compute wave drift force, two different seakeeping programs are used: AdFLOW based on Wave Green function method and SWAN based on Rankine panel method. When wave drift force is calculated using SWAN program, not only ship forward speed but also ship lateral speed are considered. By doing this, effects of lateral speed on wave drift force and maneuvering performance in waves are confirmed. The developed method is validated by comparing turning test results in regular waves with existing experimental data. Sensitivities of wave drift force on maneuvering performance are, also, checked.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.506-515
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• 2020

Surfing is a sport sensitive to changes in the natural environment, using naturally occurring waves. In other words, factors such as the construction of coastal structures, coastal erosion, and sediment transportation could cause the wave to change into a direction inappropriate for surfing at the shore where surfable waves were reaching. In this study, we call the characteristics of the coastal environment that affect the formation of surfable waves as surfing resources, which is subsequently analyzed by coastal engineering methodologies. Also, using Delft3D-WAVE module (SWAN model), a way to evaluate sustainability of surfable wave is suggested through analysis of surfing resources at Jukdo, Yangyang, Gangwon Province, Republic of Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.557-564
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• 2007

The effect of wave and current interactions on regular wave transformation over a submerged elliptic shoal is investigated based on numerical simulations of the Vincent and Briggs experiment [Vincent, C.L., Briggs, M.J., 1989. Refraction-diffraction of irregular waves over a mound. Journal of Waterway, Port, Coastal and Ocean Engineering, 115(2), pp. 269-284]. The numerical simulations are conducted by constituting two numerical model systems: a combination of SWAN(a wave model) plus SHORECIRC(a current model) and a combination of REF/DIF 1(a wave model) plus SHORECIRC. A time dependent phase-resolving wave-current model, FUNWAVE, is also utilized to simulate the experiment. In the simulations, the breaking-induced currents defocus waves behind the shoal and bring on a wave shadow zone that shows relatively low wave height distributions. The computed results of the two model systems agree better with the measurements than the computed results obtained by neglecting wave-current interaction do. However, it is found that the radiation stresses for standing waves are misevaluated in the wave models. In addition, the results of FUNWAVE show very good agreement with the measurements. The agreement indicates that it is necessary to take into account the effect of breaking-induced current on wave refraction when wave-breaking occurs over a submerged shoal.

• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.75-81
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• 2021

Artificial Coral Reefs (ACRs) have been introduced to help solve coastal erosion problems, but their feasibility has not been assessed with field data. This study conducted a feasibility analysis of ACRs on their erosion mitigation effects by performing a case study of Cheonjin-Bongpo beach, South Korea. A numerical-physical combined analysis was carried out using a SWAN model simulation and physical model test with a scale of 1/25 based on field observations of Cheonjin-Bongpo beach. Both Dean's parameter and the surf-scaling parameter were applied to comparative analysis between the absence and presence conditions of the ACR. The results for this combined method indicate that ACR attenuates the wave height significantly (59~71%). Furthermore, ACR helps decrease the mass flux (~50%), undertow (~80%), and maximum wave set up (~61%). The decreases in Dean's parameter (~66%) and the surf-scaling parameter suggest that the wave properties changed from the dissipative type to the reflective type even under high wave conditions. Consequently, an ACR can enhance shoreline stability.