• Title/Summary/Keyword: Shallow water region

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The geophysical survey in shallow water and transitional region

  • Ashida Yuzuru
    • 한국지구물리탐사학회:학술대회논문집
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    • 2002.09a
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    • pp.1-15
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    • 2002
  • In the present paper, the marine reflection seismic survey, the survey using Chirp sonar, the detail topographic survey by narrow multi-beam sounding machine, the sea bottom geological condition survey by side-scan sonar, the sea bottom sampling by core sampler and the positioning by DGPS as the geophysical survey in shallow and transitional region are introduced by placing emphasis on hardware configuration.

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A Study on the Resistance Characteristics of High-Speed Ship in Shallow Water Condition (천수영역에서 고속선박의 저항특성에 대한 연구)

  • 권수연;이영길
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.2
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    • pp.1-11
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    • 2004
  • In this paper, the resistance characteristics of high-speed ship are studied in the region of shallow water condition. For the purpose of this research, model tests in a ship model basin are carried out with an equipment for the satisfaction of shallow water condition, and the computions of wave resistance characteristics and the flow simulations around a ship hull are performed by Michell's thin ship theory and a finite difference method based on MAC scheme, respectively. The calculation results for the resistance and flow characteristics of a ship hull are compared with those from the model tests in deep and shallow water conditions. From the comparison results, it is known that the variation of wave pattern around a ship hull caused by shallow water condition has the most influence to the resistance characteristics of a high-speed ship advancing on shallow water.

Shoaling Prediction by the Statistical Joint Distribution in the Shallow Water Region (천해역에 있어서의 결합확률분포의 천수변형에 대한 연구)

  • 권정곤
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.1
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    • pp.14-20
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    • 1991
  • Accurate estimation of irregular wave transformation when the waves propagate from deep water to shallow water region is very important for the design of coastal structures and establishing beach erosion control. In this study. the transformation of directional spectrum is tested numerically using a conservation equation for energy flux and. based upon the joint distribution of wave height. period and wave direction. shoaling effects are predicted in the shallow water region. The applicability of the proposed procedure is verified through comparison with field observation data.

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Numerical Simulation of Longshore Current due to Random Sea Waves (불규칙파에 의한 연안류의 수치계산)

  • 권정곤;양윤모
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.4 no.2
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    • pp.72-82
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    • 1992
  • To accurately estimate nearshore current in shallow water regions. it is necessary to investigate the irregular wave transformation characteristics and radiation stress produced by random sea waves. This research is to investigate the application or the individual wave Analysis Method. the Component Wave Analysis Method and Representative Wave Analysis Method in the shallow water region. These methods were estimated by wave shallowing transformation when the waves propagate from deep water to shallow water region b)r generating regular waves, two component waves and irregular waves (Bretschneider-Mitsuyasu type). That is, the Indivisual Wave Analysis Method is to investigate from the viewpoint of shallow water transformation of wave statistical characteristics and their zero-down-crossing waves (wave height period and wave celerity). And the component Wave Analysis Method is to investigate from the view point of shallow water transformation of basic frequency component wave and their interference frequency component wave. In addition, this research is to compare the measured mean water level elevation with the calculated one from radiation stress of irreguar waves that is assumed in the three methods above.

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The Design Development on the Mooring System of a Floating Barge Positioned in the Shallow Water Zone (천해역에 위치한 바지형 부유체의 계류시스템 설계)

  • Kim, Young-Bok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.5
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    • pp.364-371
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    • 2015
  • This study is aimed to develop the dynamic analysis technique for a floating aquaculture in a shallow water region under the harsh sea condition. In case of the installation region to transform from a coastal area to the offshore area, the influence of sea bed with sea waves on the mooring lines was announced to be significant by other authors. In this study, the numerical tool was developed to solve dynamic behavior of the floating barge coupled with mooring lines in a shallow zone of the sea considering the influence of sea bed on the floating system.

Nonlinear Wave Forces on an Offshore Wind Turbine Foundation in Shallow Waters

  • Choi, Sung-Jin;Lee, Kwang-Ho;Hong, Keyyoung;Shin, Seong-Ho;Gudmestad, O.T.
    • International Journal of Ocean System Engineering
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    • v.3 no.2
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    • pp.68-76
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    • 2013
  • In this study, a 3D numerical model was used to predict nonlinear wave forces on a cylindrical pile installed in a shallow water region. The model was based on solving the viscous and incompressible Navier-Stokes equations for a two-phase flow (water and air) model and the volume of fluid method for treating the free surface of water. A new application was developed based on the cut-cell method to allow easy installation of complicated obstacles (e.g., bottom geometry and cylindrical pile) in a computational domain. Free-surface elevation, water particle velocities, and inline wave forces were calculated, and the results show good agreement with experimental data obtained by the Danish Hydraulic Institute. The simulation results revealed that the proposed model can, without the use of empirical formulas (i.e., Morison equation) and additional wave analysis models, reliably predict non-linear wave forces on an offshore wind turbine foundation installed in a shallow water region.

Wave Transformation in the Intersecting Wave Trains (2방향 파랑하에서 파의 변형)

  • 김경호;조재희;윤영호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.313-320
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    • 1995
  • A numerical analysis on the wave deformation in the shallow water region is performed for the case of two intersecting wave trains of the same frequency on uniformly sloping beaches. This model is based on the consideration of wave energy balance and wave action conservation, and iteratively solved the set of conservation equations of both mass and horizontal momentum. Using the computed results, the wave deformations in accordance with the variation of the parameters luck as incident wave angie and wave height in deep water which influences the variation of wave hight and mean water level under the intersecting wave trains in the shallow water region. are considered.

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An Experimental Study on Shallow Water Effect in Slamming (천수에서의 슬래밍 현상에 대한 실험적 연구)

  • Kang, Hyo-Dong;Oh, Seung-Hoon;Kwon, Sun-Hong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.1
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    • pp.60-66
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    • 2009
  • This study presents an experimental investigation of the shallow water impact of a box type structure. The analysis was done based on the video images captured by a high speed camera, the flow field obtained by PIV (Particle Image Velocimetry), and pressure measurements in the divided region. The video images showed quite good agreement with the description given by Korobkin. The PIV measurements of the velocity field provided a clear view of the flow pattern for all three stages. The pressure was measured at the bottom of the tank with strain gauge type pressure gauges. The pressure measurements showed the characteristics of divided regions.

Dispersion Analysis of Surface Discharged Heat Water In Shallow Coastal Area (천해역에서의 표층온배수 확산해석)

  • 서승원;김덕호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.340-345
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    • 1995
  • Dispersion characteristics of surface discharge heat water in shallow region are investigated for coastal power plant with nearly constant depth of 20 meters by observing the seasonal depthwide temperature in several stations, which give or precise horizontal distribution and vertical structure of heat water. Surface discharged heat water in shallow coast in the Yellow Sea relies mainly on ambient tidal flow. so it behaves as free jet when the ambient now is strong and shows plumelike behavior during stagnant tide. According to observation the neat field region is estimated as 200-300 meters and shows distinct vertical profile and exponentially decreasing pattern from discharge point for this region. But there are no remarkable vertical distortion of temperature beyond 800 meters even though it is discharged from surface. Characteristic length scale model, CORMIX3, is applied and compared with the field date Overall tendency of CORMIX3 results resemble well with field data especially in near field and intermediate region.

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