• Title/Summary/Keyword: Wave transformation model

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Prediction Wave Transformation in the Kwangan Beach (광안해역에서의 파랑변형예측)

  • 박정철;김재중;이정만
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.04a
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    • pp.75-81
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    • 2000
  • Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develop as wave-current equation type to investigate the effect of wave-current interaction. This wave-current model was applied to the Kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

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Prediction of Wave Transformation in the Kwangan Beach (광안해역에서의 파랑변형예측)

  • 박정철;김재중;김인철
    • Journal of Ocean Engineering and Technology
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    • v.15 no.2
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    • pp.6-10
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    • 2001
  • Water waves propagate over irregular bottom bathymetry are transformed by refraction, diffraction, shoaling, reflection etc. Principal factor of wave transform is bottom bathymetry, but in case of current field, current is another important factor which effect wave transformation. The governing equation of this study is develope as wave-current equation type to investigate the effect of wave-current interaction. It starts from Berkhoff's(1972) mild slope equation and is transformed to time-dependent hyperbolic type equation by using variational principal. Finally the governing equation is shown as a parabolic type equation by splitting method. This wave-current model was applied to the kwangan beach which is located at Pusan. The numerical simulation results of this model show the characteristics of wave transformation and flow pattern around the Kwangan beach fairly well.

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Prediction Wave Transformation for Using Wave Spceturm (스펙트럼을 이용한 파랑변형 예측)

  • 박정철;김재중
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1999.10a
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    • pp.235-242
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    • 1999
  • Wave which propagate from the offshore cause transformation of diffraction, refraction, and reflection etc. in coming in the coastal by depth change. Especially, Wave strongly show the charcateristics of rancom wave in the coastal zone. Developed wave model until a recent date analysed regular waves with height and period equal to those of the significant wave, In case of Monochromatic wave, it can be analysed fine in the offshore, but differ from in coastal zone. In this study, form of governing equation is parabolic mild slope equation. This model calculated random wave for using frequency spectrum and directional spectrum from input data condition of wave. This model is applied to Vincent shoal and compared with laboratory experimental data. The results agreed well with laboratory data.

A Numerical Study of Wave Transformation on a Permeable Structure Considering Porous Media Flow (투수층의 흐름을 고려한 투수성 구조물의 파랑변형에 관한 수치적 해석)

  • Kim, In-Chul
    • Journal of Ocean Engineering and Technology
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    • v.20 no.6 s.73
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    • pp.35-40
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    • 2006
  • In recent years, there's been strong demand for seawalls that havea gentle slope and permeability that serveswater affinity and disaster prevention from wave attack. The aim of this study is to examine wave transformation, including wave run-up that propagates on the coastal structures. A numerical model based on the weak nonlinear dispersive Boussinesq equation, together with the unsteady nonlinear Darcy law for fluid motion in permeable layer, is developed. The applicability of this numerical model is examined through Deguchi and Moriwaki's hydraulic model test on the permeable slopes. From this study, it is found that the proposed numerical model can predict wave transformation and run-up on the gentle slope with a permeable layer, but can't show accurate results for slopes steeper than about 1:10.

Numerical Model Experiments of Wave Transformation for the Marine Structure Design (해양구조물 설계를 위한 파랑변형 수치모형실험)

  • Jang, Ho-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.3
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    • pp.440-447
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    • 2012
  • Numerical model experiments of wave transformation due to the reclamation and the construction of breakwater in case of 50 years design wave were performed using time dependent mild slope equation included shoaling, refraction, diffraction, reflection and wave breaking. As waves propagate to the shore, wave height gradually diminishes by the bottom friction and wave breaking etc.. After the reclamation and the construction of 75 m length breakwater, wave height distributions in the lee of breakwater have the range of 29~128 cm. To make better the harbor tranquility the length of breakwater needs to extend more than 100 m. After the construction of breakwater, wave height in the lee of the structure was deduced over 80%.

Wave propagation in a FG circular plate via the physical neutral surface concept

  • She, Gui-Lin;Ding, Hao-Xuan;Zhang, Yi-Wen
    • Structural Engineering and Mechanics
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    • v.82 no.2
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    • pp.225-232
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    • 2022
  • In this paper, the physical neutral surface concept is applied to study the wave propagation of functionally graded (FG) circular plate, the wave equation is derived by Hamiltonian variational principle and the first-order shear deformation plate model. Then, we convert the equations to dimensionless equations. The exact solution of wave propagation problem is obtained by Laplace integral transformation, the first order Hankel integral transformation and the zero order Hankel integral transformation. The results obtained by the current model are very close to those obtained in the existing literature, which indicates the correctness and reliability of this study. Moreover, the effects of the functionally graded index parameters and pore volume fraction on the wave propagation are also discussed in detail.

An Analysis of Wave Height Distribution in the Vicinity of Samcheon New-Harbor (삼천포 신항의 파고분포 해석)

  • Jang, Dae-Jeong;Ham, Gye-Un
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.39-46
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    • 2010
  • The calmness inside a harbor plays an important role in the appropriate disposition of harbor structures. However, it is not easy to acquire accurate computational results because these are affected by many factors concerned with wave transformation. Recently, numerical model tests, which are quicker and more economical than hydraulic model experiments, were carried out for the purpose of analyzing wave height distributions in harbors. This paper presents a numerical model that is able to calculate wave heights inside a harbor. It is based on a time-dependent mild slope involving wave refraction, diffraction, shoaling effect, and reflection. In particular, arbitrary reflectivity is used at the boundary in order to simulate the real harbor reflection condition. The proposed numerical model is applied to Samcheon new-harbor in order to investigate harbor calmness.

Hybrid finite element model for wave transformation analysis (파랑 변형 해석을 위한 복합 유한요소 모형)

  • Jung Tae Hwa;Park Woo Sun;Suh Kyung Duck
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.209-212
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    • 2002
  • Since Berkhoff proposed the mild-slope equation in 1972, it has widely been used for calculation of shallow water wave transformation. Recently, it was extended to give an extended mild-slope equation, which includes the bottom slope squared term and bottom curvature term so as to be capable of modeling wave transformation on rapidly varying topography. These equations were derived by integrating the Laplace equation vertically. In the present study, we develop a finite element model to solve the Laplace equation directly while keeping the same computational efficiency as the mild-slope equation. This model assumes the vertical variation of wave potential as a cosine hyperbolic function as done in the derivation of the mild-slope equation, and the Galerkin method is used to discretize . The computational domain was discretized with proper finite elements, while the radiation condition at infinity was treated by introducing the concept of an infinite element. The upper boundary condition can be either free surface or a solid structure. The applicability of the developed model was verified through example analyses of two-dimensional wave reflection and transmission. .

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Elliptic Numerical Wave Model Solving Modified Mild Slope Equation (수정완경사방정식의 타원형 수치모형)

  • YOON JONG-TAE
    • Journal of Ocean Engineering and Technology
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    • v.18 no.4 s.59
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    • pp.40-45
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    • 2004
  • An efficient numerical model of the modified mild slope equation, based on the robust iterative method is presented. The model developed is verified against other numerical experimental results, related to wave reflection from an arc-shaped bar and wave transformation over a circular shoal. The results show that the modified mild slope equation model is capable of producing accurate results for wave propagation in a region where water depth varies substantially, while the conventional mild slope equation model yeilds large errors, as the mild slope assumption is violated.

Numerical Simulation of Irregular Wave Transformation due to Wave-induced Current over a Submerged Elliptic Shoal (수중타원형 천퇴상 불규칙파의 파랑쇄파류에 의한 변형 수치모의)

  • Choi, Jun-Woo;Baek, Un-Il;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.6
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    • pp.565-573
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    • 2007
  • The effect of wave and current interactions on irregular 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 a combination of REF/DIF S(a wave model) and SHORECIRC(a current model) and a time dependent phase-resolving wavecurrent model, FUNWAVE. 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 combined model system agree better with the measurements than the computed results obtained by neglecting wave-current interaction do. In addition, the results of FUNWAVE show a 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.