• Title/Summary/Keyword: Boussinesq방정식

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Development of Weakly Nonlinear Wave Model and Its Numerical Simulation (약비선형 파랑 모형의 수립 및 수치모의)

  • 이정렬;박찬성
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.4
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    • pp.181-189
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    • 2000
  • A weakly nonlinear mild-slope equation has been derived directly from the continuity equation with the aid of the Galerkin's method. The equation is combined with the momentum equations defined at the mean water level. A single component model has also been obtained in terms of the surface displacement. The linearized form is completely identical with the time-dependent mild-slope equation proposed by Smith and Sprinks(1975). For the verification purposes of the present nonlinear model, the degenerate forms were compared with Airy(1845)'s non-dispersive nonlinear wave equation, classical Boussinesq equation, andsecond¬order permanent Stokes waves. In this study, the present nonlinear wave equations are discretized by the approximate factorization techniques so that a tridiagonal matrix solver is used for each direction. Through the comparison with physical experiments, nonlinear wave model capacity was examined and the overall agreement was obtained.

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Analysis of Generation and Amplification Mechanism of Abnormal Waves Occurred along the West Coast of Korea (서해안 이상파랑의 발생 및 증폭 기구 분석)

  • Yoon, Sung Bum;Shin, Choong Hun;Bae, Jae Seok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.5
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    • pp.314-326
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    • 2014
  • On 31 March 2007, the abnormal wave occurred along the western coast of Korea. In order to investigate the generation mechanism of abnormal waves and to understand the amplification process of the abnormal waves, the observed data were analyzed and one-dimensional numerical model experiments were performed by using both the linear shallow water equation and the linear Boussinesq equation models. Various types of pressure jump for the abnormal waves previously proposed by other researchers were reviewed. As a result, it was not possible to reproduce the abnormal waves from the previously proposed pressure jumps. In this study, we proposed a new form of pressure jump, and numerical simulations were performed in order to check the validity of the proposed pressure jump. The numerical results showed that the calculated period of abnormal waves and the maximum water elevations agreed reasonably well with those of the observations.

Evaluation of Fluid Forces Acting on Offshore Structures Placed in the Vicinity of Underwater Shoal (수중 천퇴 인근에 설치된 해양구조물에 작용하는 유체력 결정에 대한 고찰)

  • Chun, In-Sik;Min, In-Ki;Sim, Jae-Seol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.136-145
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    • 2007
  • When waves propagating over an underwater shoal break at the top of the shoal, wave heights are drastically decreased in the downstream breaking zone, but a secondary current shooting downstream with strong velocity can be induced by the breaking waves themselves. In the case that an offshore structure is placed in the breaking zone, the estimation of wave farce purely based on the visible wave height may cause an under-design of the structure. Thus, for the safe design of the structure, the breaking wave induced current should be necessarily considered in the comprehensive estimation of design load. In the present study, Boussinesq equation model to calculate the wave height distribution and breaking wave induced current was set up and applied to the scheme of a hydraulic model test previously undertaken. Based on the results of the Boussinesq model, fluid forces acting on the model structure were calculated and compared with the experimental results. The importance of the breaking wave induced current was quantitatively assessed by comparing fluid forces with or without current.

Analysis of Traffic Safety and Harbor Tranquility due to Port Expansion (항만확장에 따른 통항안전 및 항만정온도 검토)

  • Moon, Seung-Hyo;Kwon, Seong-Min;Lee, Joong-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.64-67
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    • 2017
  • 화물량이나 해상관광객 유입 확대 등 항만수요의 증가에 따른 대응으로 항만을 확장하거나 신규항만을 계획하게 된다. 우리나라 어항의 경우 경관이 수려하고 청정지역으로 분류되어 개발여지가 크다. 이중 감포항의 경우도 해상을 통한 연안 화물의 운송확장과 어항의 기능에서 연안항의 여건을 갖추고 경주와 연계한 해양 관광벨트를 구성하여 친수공간 조성, 송대말 등대 컨텐츠 사업 등 해양관광의 거점으로 도약하기 위한 집중개발을 추진 중에 있어서 종합적인 관점에서 항만확장을 검토할 필요가 있다. 본 연구는 추진 중인 항만확장과 관련하여 남측 및 동측의 항만확장안에 대해 선박의 통항안전 및 계류한계파고에 대한 항만 정온도 여부를 제 3세대 수치파랑 모형인 SWAN모형과 강비선형 Boussinesq 방정식을 적용한 불규칙파 Bouss-2D 모형을 적용하여 모형간 특성을 도출한 후 현재안과 각 대안별로 파랑반응특성을 비교분석하였다. 이에 대한 결과는 각 대안별로 장래 항만확장에 대한 기초자료로 활용될 수 있을 것이다.

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Numerical Simulation of Solute Transport in Coastal Areas (해안지역에서의 용존성 물질의 이송확산 거동 수치모의)

  • Kim, Dae-Hong
    • Ecology and Resilient Infrastructure
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    • v.1 no.1
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    • pp.1-7
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    • 2014
  • In this study, a numerical simulation technique for coastal area where wave and current interactions are observed is proposed. Considering the spatial scale of coastal area and the coastal processes such as wave, current, shoaling, wave breaking, and inundation processes, boussinesq equation model is used. A depth-integrated transport model based on the consistent assumption with the boussinesq equation model is used for the prediction of solute transport. To solve the equations, finite volume method with an approximate riemann solver is used. The proposed model is applied to a coastal area and reasonable computational results are obtained.

On the Study of Nonlinear Wave Diffraction by the Breakwaters (방파제 주위에서의 비선형 회절 현상에 대한 고색)

  • 조일형;김장환
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.5 no.4
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    • pp.350-356
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    • 1993
  • We carry out a numerical calculation to understand the nonlinear wave deformation around breakwaters using the Boussinesq equation, which is weakly nonlinear and weakly dispersive shallow water equation. A numerical method based on a finite element scheme and fourth order Runge-Kutta algorithm is employed to investigate the diffraction of incident waves by the breakwater. As a computational model, two-dimensional wave flume is treated. The breakwaters is perpendicular to the side wall of a channel. From the numerical results, the wave deformations according to the change of the length and the thickness of breakwaters are investigated. We also investigate the effect of the nonlinearity by comparing the results with the linear solutions.

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