• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.301-307
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• 2006

In coastal zones with high tidal ranges like Korean western coast, port construction and reclamation projects have been increased. Most of the projects include sea-dyke construction. In the sea-dykes constructed to protect sea water intrusion, sea water was exchanged through the permeable dykes. The water level inside the area enclosed by the dykes changes with time due to tidal action of outer sea, but the tidal range is smaller than that of outside because of strong friction. In numerical modeling of coastal circulation the water exchange through the dykes has been neglected, which has produced inaccurate estimation neglecting the water exchange. In this study a method, which can consider water exchange through sea-dyke, was suggested and the modeling accuracy was improved. A groundwater theory was utilized to explain the phenomena.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.22-28
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• 2004

A mathematical model has been developed to evaluate the capability of sea water exchanges under tidal and diffusive environments and has been verified through comparison with numerical experiments. From the mathematical analysis, this study presents the rates of sea water exchanges due to the tidal inflow and diffusion process. The port characteristic length $L_p$ is the most significant evaluation index.

• Journal of Ocean Engineering and Technology
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• v.24 no.3
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• pp.21-30
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• 2010

This study presents a numerical simulation of sea water-exchange as a preliminary accessing tool of water quality in the protected shore behind a overtopped breakwater. The overtopped breakwater is taken into account for a safe swimming and beach protection. The overtopping rate is calculated by empirical models and the consequent currents, known as wave-induced currents, are calculated under the conditions of H.W.O.S.T and L.W.O.S.T. The rate of sea water exchange is used to evaluate the characteristics of sea water exchange and calculated through the simulation processes such as advective discharging through the outlets and random-walking diffusion of particles released within a basin. The numerical results show that the overtopped waves sufficiently improve the water exchange without healthless stagnation of contaminated mass and the consequent currents are not too strong for swimming.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.11-19
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• 2000

This study aims to examine the characteristics of the water quality variation in relation to the change of water exchange rate with respect to the development phases of the Pusan port. To clarify the characteristics, water exchange caused by the variations of coastline shape and water surface area was examined by the numerical experiments using the Lagrangian particle tracking model based on 2-D shallow water equation. As the results of numerical experiments, it was proved that the water exchange in the Pusan port was decreased mainly due to the port development and the breakwaters construction. During the port development phases from 1875 to 1998, 35% of the sea-space in the port had decreased to make hinterland spaces. This resulted in the loss of wet-land and coastline change as well as decrease of the water exchange rate at the sea side. The city population in that period had rapidly increased from several thousands to 4 millions, resulting in the large discharge of sewages into the port area. Under the these environmental conditions, it can be clearly said that the water quality in the Pusan port is sensitively affected by the discharge of urban sewages decrease of the water exchange rate in relation to port and urban developments. In the study, the temporal changes of water quality were discussed with respect to the port development phases. It was clear that the water quality wad controlled by the exchange rate change under the port development as well as the input impact into the port from the urbanized city area. To make clean sea of the Pusan port, it is suggested that the sewage control, the water exchange and coastline control should be systematically checked under the concept of eco-friendly development and environmental management.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.227-233
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• 2002

Recently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes u\\various environmental impacts. In this study, water flow system of Danghnag Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically. In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity. In addition, numerical model for tidal exchange is developed considering conditions of Danghang Bay. Calculated results show good agreement with measurement. Lastly, based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.

• Journal of the korean society of oceanography
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• v.37 no.3
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• pp.169-177
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• 2002

An eddy-resolving free-surface primitive-equation model with nonlinear terrain-following coordinates is established to study the exchange of water masses among the Asian marginal seas and their adjacent waters. A curvilinear coordinate system is used to generate the horizontal grid with a variable resolution for the regional oceans from $5^{\circ}$S to $45^{\circ}$N and $100^{\circ}$E to $155^{\circ}$E. The higher resolution region has about a 10 km by 10 km grid covering the complex geometry of the coastal marginal seas, while the lower resolution region has about a 30 km by 30 km grid covering the eastern Pacific. The model is initialized by the Levitus annual climitology and forced by the monthly mean air-sea fluxes of momentum, heat, and freshwater derived from the Comprehensive Ocean-Atmosphere Data Set. High-resolution and low-viscosity are identified as the key factors for a better representation of the exchange of waters through narrow straits and passages between the marginal seas and their adjacent waters. The dynamics of the loop currents and eddies in the South China Sea and Celebes Sea are examined in detail. It has found that the anticyclonic loop and detached eddies from the Kuroshio through the Luzon Strait play an important role in transporting warm and salty water into the South China Sea, while the cyclonic circulation of the Mindanao Current in the Celebes Sea plays a role in contributing cold water to the Indonesian throughflow. The deep undercurrent of the western Pacific is shown to provide fresher water to the South China Sea and Celebes Sea. These modeling results suggest that the exchange processes via the narrow straits and passages are of fundamental importance to the maintenance of water masses for the marginal sea region.

• Journal of Korea Water Resources Association
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• v.31 no.2
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• pp.209-219
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• 1998

Sea water volume intruded from the lock gated was compted by a one-dimensional numerical model and the extent of diffusion of sea water was evaluated for that. The volume of intruded sea water, in the exchange processes of salt and fresh waters, was computed by the conceptual model considering the tidal level, volume of chamber, volume of canal, and operation period only, It was divided into some cases according to whether ships enter or leave the canal and whether the level of tide is lower or higher than that of water level in canal. The model, developed in this work, assumed that intruded sea water is well mixed in the canal; and complete is the exchange of waters between sea and canal. The simulation case was divided into two categories according to whether the water was added from the Han River or not.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.89-94
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• 2009

This study aims to examine the the characteristics if the sea water circulation in related to the change of the water exchange rate according to the the development phases of Busan Port. To clarify the characteristics, the water exchange caused by construction if new-port and river discharge conditions was examined by the numerical experiments using the Lagrangian particle tracking model based on 2-D shallow water equation. This study deals with the charge of flow field and water exchange after redevelopment using numerical simulation technique, based on the field observation and 4 rivers discharge flow. As a result if numerical simulation, Variation if current velocity in Busan North Port is almost nothing before and after construction. Water exchange of channel in area of redevelopment is a little. Futhermore, the tidal exchange had a tendency to be small both before and after redevelopment by 60%.

• Journal of the korean society of oceanography
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• v.37 no.3
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• pp.125-133
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• 2002

Water and salt budgets in the Yellow Sea and Bohai are analyzed based on the historical data and CTD data collected recently using box models. The amounts of volume transport and of water exchange across the boundary between the Yellow and East China Seas are estimated to be 2,330-2,840 $\textrm{km}^3$/yr and 109-133 $\textrm{km}^3$/yr, respectively, from the one-layer box model. Corresponding water residence time is 5-6 years. In the Bohai, water residence time is twice as long as that in the Yellow Sea, suggesting that the Yellow Sea and Bohai cannot be considered as a single system in the view of water and salt budgets. The results indicate that water and salt budgets in the Yellow Sea depend almost only on the water exchange between the Yellow and East China Seas. The computation with the coupled two-layer model shows that water residence time is slightly decreased to 4-5 years for the Yellow Sea. In order to reduce uncertainties for the budgeting results the amount of the discharge from the Changjiang that enters into the Yellow Sea, the vertical advection and vertical mixing fluxes across the layer interface have to be quantified. The decreasing trend of the annual Yellow River outflow is likely to result that water residence time is much longer than the current state, especially for the Bohai. The completion of the Three Gorges dam on the Changjiang may be change the water and salt budgets in the Yellow Sea. It is expected that cutting back the discharge from the Changjiang by 10% through the dam would increase water residence time by about 10%.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.124.2-124.2
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• 2010

Generally, a coolant of the nuclear power plant is manufactured by electrolyzing the sea water near the plant for making the sodium hypochlorite(NaOCl), which is used for sterilizing the bacteria and the shellfishes sticking to the drains or the pumps at the outlet of the cooling system due to $8-10^{\circ}C$ warmer temperature than the inlet sea water. During manufacturing the sodium hypochlorite, the hydrogen with the high purity is also produced at the anode side of the electrolyzer. This paper describes a novel power plant system combined with the polymer electrolyte membrane(PEM) fuel cell, the wasted hydrogen from the sea water electrolyzer and the wasted heat of the nuclear power plant. The present status over the exhausted hydrogen at twenty nuclear power plants in Korea was investigated in this study, from which an available power generation is estimated. Furthermore, the economic feasibility of the PEM fuel cell power plant is also evaluated by a current regulations over the power production and exchange using a renewable energy shown in Korea Power Exchange(KRX).