• Title/Summary/Keyword: tidal range

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A Numerical Experiment On Tidal Currents In Asan Bay

  • Ahn, Hui Soo;Lee, Suk Woo
    • 한국해양학회지
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    • v.11 no.1
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    • pp.18-24
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    • 1976
  • The distribution of tidal currents in Asan Bay was simulated by a numerical experiment. A homogeneous and single layer model with bottom stress taken into account was used. Although the effective configuration of the bay differs significantly between the high tide and the low tkde, its form is assumed to be fixed as a first approximation. The advective term is particularly large because the tidal range of 810cm is large compared to the depth and the changes of velocities occur abruptly. The results of calculations agree fairly well with the observations. For example, the tidal range at Manhoriis amplified 15cm higher and the phase lag is five minutes later than at the mouth of the bay. It also can generally be said that, with the semidiurnal tide at the mouth of the bay, the tidal range is increased toward the inner corner and that tidal currents are found to be large at the deeper part of the bay.

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Beach Erosion during Storm Surge Overlapped with Tide (조위변동을 고려한 폭풍해일시의 해안침식에 관한 연구)

  • 손창배
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.6 no.2
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    • pp.47-56
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    • 2000
  • This paper describes a simple prediction method of beach recession induced by storm surge. In order to evaluate the severest beach erosion, it is assumed that maximum beach recession occurs at the coming of storm surge overlapped with spring tide. Consequently, total surge lev디 becomes the sum of storm surge level and tidal range. Generally, storm surge level around Korea is small compared with tidal range. Therefore total surge can be expressed as the series of surges, which have same duration as tide. Through the case studies, the author Investigates correlation between tidal range, duration, wave condition, beach slope and beach recession.

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Analysis of Hydraulic Effects of Singok Submerged Weir in the Lower Han River (한강하류부 신곡수중보의 수리학적 영향분석)

  • Kim, Sang-Ho;Kim, Won;Lee, Eul-Rae;Choi, Kyu-Hyun
    • Journal of Korea Water Resources Association
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    • v.38 no.5 s.154
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    • pp.401-413
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    • 2005
  • This study analyzed the hydraulic effects of Singok submerged weir in the lower Han River. 1-D hydraulic flood routing model was used and calibration and verification were performed using 8 flood or nonflood events. Flow characteristics were analyzed using various outflows of Paldang Dam and tidal data of the Yellow Sea. Water level increase effects by establishment of Singok submerged weir were as following, when maximum flood tidal was 2.4m, highest water level increased about 0.65m, and lowest water level increased about 1.25m in the downstream of Jamsil submerged weir. In Hangang Bridge, due to the Singok submerged weir, when maximum flood tidal was 2.4m, tidal range was 0.07m and decrement of tidal range was about $90\%$. And when maximum flood tidal was 5.5m, tidal range was 1.6m and decrement of tidal range was about $35\%$. When the outflow of Paldang Dam was over 20,000cms, tidal range was below about 0.06m, and tidal effect did not appear hardly.

Resource Assessment of Theoretical Potential of Ocean Energy in Korea (국내 해양에너지 이론적 잠재량 산정 연구)

  • HWANG, SUJIN;JO, CHULHEE
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.5
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    • pp.465-472
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    • 2019
  • This paper describes the resource assessment of theoretical potential of ocean energy including tidal current energy, tidal range energy, wave energy and ocean thermal energy in Korea to provide reliable basis for feasible development plan of ocean energy. Because of different characteristics of each ocean energy resources, the resource assessment methods were established considering characteristics of each ocean energy resources. The coastal region of Korea has been divided into 10 regions. The results show that tidal current energy is abundant in Incheon-Gyunggi and Jeollanam-do and tidal range energy is abundant in Incheon-Gyunggi. And wave energy is abundant in Jeollanam-do, Jeju and Gyeongsangbuk-do and there is ocean thermal energy in Gangwon-do and Gyeongsangbuk-do.

On the Tides, Tidal Currents and Tidal Prisms at Inchon Harbor (인천항의 조석, 조류 및 조량에 대하여)

  • Yi, Sok-U
    • 한국해양학회지
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    • v.7 no.2
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    • pp.86-97
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    • 1972
  • The tides, tidal currents and tidal prisms at Inchon Harbor are studied with recent data. The tides at Inchon Harbor is of semi-diurnal type having a spring range of 798cm and a phase age of 2 days. The monthly mean sea level at Inchon has a maximum at August and a minimum at January with a annual range of about 40cm. the tidal currents at Inchon Outer Harbor are of semi-diurnal type same as tides and nearly reversing type. The flood and ebb currents set north and south with a velocity of about 90-175 cm/sec and 120-225 cm/sec at spring tide and begin 0.2 hours after L.W. and 0.7 hours after H. W., respectively. Non-tidal currents flow southward with 10-20 cm/sec at west side of the stream and northward with 15-20 cm/sec at east side of the stream at Inchon Outer Harbor. The flood volume through the Inchon Outer Harbor fluctuates fortnightly from 590 10$\^$6/㎥ spring tide to 260 $10^6/m^3$ at neap tide and ebb volume changes from 470 $10^6/m^3$ at spring tide to 200 $10^6/m^3$ at neap tide, respectively. The flow area along the channel to the Estuary of Yeomha is controlled by the tidal prism as expressed by $A=1.14{\times}10^{-4}P^{0.966}$

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Vertical Axis Tidal Turbine Design and CFD hydrodynamic Analysis (CFD를 이용한 수직축 터빈 설계 및 유동특성 분석)

  • Jo, Chulhee;Ko, Kwangoh;Lee, Junho;Rho, Yuho;Lee, Kanghee
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.159.1-159.1
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    • 2011
  • Due to the global warming, the need to secure the alternative resources has become more important worldwide. Having very strong current on the west coast with up to 10 m tidal range, there are many suitable sites for the application of TCP(Tidal current power) in Korea. Not only from the current produced from the high tidal range, but also it can be widely applied to the offshore jetties and piers. The VAT(Vertical axis turbine) system could be very effective tidal device to extract the energies from the attacking flow to the structures. For the relatively slow current speed, the VAT system could be more effective application than HAT(Horizontal axis turbine) device. The performance of VAT can be evaluated by various parameters including number of blades, shape, sectional size, diameters and etc. The paper introduces the multi-layer vertical axis tidal current power system with savonius turbine. The turbine was designed with consideration of optimal blade numbers and the performance was simulated by CFD analysis.

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Analysis of Tidal Current for Cheonsu Bay Using Heaps Model (Heaps 모델을 이용한 천수만 해역의 조류해석)

  • 박영기
    • Journal of Environmental Science International
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    • v.4 no.2
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    • pp.245-251
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    • 1995
  • Generally, It is Introduced to well-known other models without considering tidal current of the field. The paper presents field measurements and numerical model solving velocity field of Cheonsu Bay by two-dimensional tidal model. It was proved that this scheme is easy to handle complex topography. Computed results is represented characteristics of tidal current for Cheonsu Bay. The results of the study can be summarized as follows ; 1. Tide form number has 0.21 value. Tidal range estimated 630.3 cm on spring, 454.1 cm on mean and 277.9 cm on neap, respectively 2. Tidal current has semi-diurnal form. Distance of traveling observed 16.6 km on flood and 15.5 km on ebb. 3. Tidal velocity showed reversing current. It was found that tidal velocity above 100 cm/sec is about 20 %. 4. Computed results are in good agreement with the observed data. Applying the algorithm to Cheonsu Bay, velocity fields and dry bank phenomena are simulated well in spite of complex topography. 5. An advanced study on the effects of open boundary conditions should be continuously performed.

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Coupling of GIS and time dependent 2-D Sediment Transport Modeling (GIS와 연동된 2차원 퇴적물이동 모델링)

  • Lim, Hak-Soo;Kim, Chang S.;Lee, Sue-Hyun;Yoo, Dong-Hoon
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2002.08a
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    • pp.208-211
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    • 2002
  • The Kyunggi Bay (125-l28E, 36-38N) is a macro-tidal bay in the western central port of Korean Peninsula(Fig. 1). The Bay characterizes its feature as wide tidal flats, deep tidal channels and tidal sand ridges running in parallel to tidal flows. The macro-tidal range (up to approximately 8.6m) and consequent strong tidal currents erode the bottom sediment and selectively transport to the low-energy area forming tidal ridges or tidal flats. (omitted)

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Numerical Modeling of Tide and Tidal Current in the Kangjin Bay, South Sea, Korea

  • Ro, Young-Jae;Jun, Woong-Sik;Jung, Kwang-Young;Eom, Hyun-Min
    • Ocean Science Journal
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    • v.42 no.3
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    • pp.153-163
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    • 2007
  • This study is based on a series of numerical modeling experiments to understand the tidal circulation in the Kangjin Bay (KB). The tidal circulation in the KB is mostly controlled by the inflow from two channels, Noryang and Daebang which introduce the open ocean water into the northern part of the KB with relatively strong tidal current, while in the southern part of the KB, shallowest region of the entire study area, weak tidal current prevails. The model prediction of the sea level agrees with observed records at skill scores exceeding 90 % in terms of the four major tidal constituents (M2, S2, K1, O1). However, the skill scores for the tidal current show relatively lower values of 87, 99, 59, 23 for the semi-major axes of the constituents, respectively. The tidal ellipse parameters in the KB are such that the semi-major axes of the ellipse for M2 range from 1.7 to 38.5 cm/s and those for S2 range from 0.5 to 14.4 cm/s. The orientations of the major-axes show parallel with the local isobath. The eccentricity values at various grid points of ellipses for M2 and S2 are very low with 0.2 and 0.06 on the average, respectively illustrating that the tidal current in the KB is strongly rectilinear. The magnitude of the tidal residual current speed in the KB is on the order of a few cm/s and its distribution pattern is very complex. One of the most prominent features is found to be the counter-clockwise eddy recirculation cell at the mouth of the Daebang Channel.

Seepage-Advection-Dispersion Numerical Analysis of Offshore Rubble Mound Revetment Landfill Under Transient Flow (비정상류 조건에서 경사식호안매립장에 대한 침투이류 분산해석)

  • Hwang, Woong-Ki;Kim, Hyang-Eun;Kim, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.4
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    • pp.1-9
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    • 2020
  • This study analyzes contaminant movement under transient flow in a rubble mound revetment offshore waste landfill barrier system that prevents contaminant runoff. The barrier system consists of bottom layer and side barrier. For the bottom layer system, impermeable clay layer is used. For the side barrier system, the HDPE barrier sheet (primary element) plays the main role, and the intermediate protection layer (supplementary element) is responsible for the barrier. Seepage, advection, dispersion numerical analysis was carried out using SEEP / W and CTRAN / W programs. As a result, under abnormal conditions considering the fluctuation in tidal range, the volume and direction of the flow velocity vector of the pore water change with time and the dispersion concentration of the contaminant changes. When comparing the case of 2 m tidal range and 8 m tidal range, the larger the tide value, the higher the concentration of contaminant under abnormal conditions. It was found that the rate of change of the concentration of the contaminant changed depending on the change in the tidal range, and as a result, the outflow of the pollutant was smaller than that in the steady flow state.