• 제목/요약/키워드: Wave transformation

검색결과 346건 처리시간 0.026초

다방향불규칙파랑장에서의 파고, 주기, 파향의 종합확률분포 유도과정 및 적합성 (On the Joint Distribution of Wave Height, Period and Wave Direction in Random Sea Waves)

  • 권정곤
    • 한국해안해양공학회지
    • /
    • 제2권2호
    • /
    • pp.75-82
    • /
    • 1990
  • 파고, 주기의 정보로서 수위변동η, 그 시간적분법η, 파향의 정보로서 수평방향 2성분 물입자속도 u, v의 4가지 시계열을 판정하여, narrow band-width frequency spectrum을 가지는 불규칙파의 포락파형(enveloped wave)을 구함으로서, 파고, 주기, 파향의 종합확률분포를 상세히 유도하여, 현지실측경과와 비교, 검토했다. 그 결과, 실측되어진 종합확률분포는 유도되어진 파고, 주기, 파향의 결합확률분포와 양호하게 일치하여 현지 불규칙파랑장에 있어서 충분한 정도로서 적용할 수 있다는 것을 알았다.

  • PDF

3차원파동장에 있어서 복수열불투과성잠제에 의한 파랑제어에 관한 연구 (Wave Control by Multi-Rowed Impermeable Submerged Breakwaters in Three-Dimensional Wave Fields)

  • 김도삼;배은훈;이봉재
    • 한국해양공학회지
    • /
    • 제15권3호
    • /
    • pp.107-113
    • /
    • 2001
  • This study is focused on the wave control by economical multi-rowed impermeable submerged breakwaters which need less materials than a one-rowed submerged breakwater. A boundary element method and eigenfunction expansion method based on the Green\`s theorem are appled to analyze the characteristics of wave transformation. Submerged breakwaters are consisted of one and two-row with rectangular section. Wave transformation characteristics are investigated by the various combinations of placement distance and crown water depth.

  • PDF

단일 잠제에 의한 파랑변형에 관한 연구 (Wave Transformation of Submerged Breakwater with One Ray)

  • 김원규;강인식;곽기석;김도삼
    • 한국항만학회지
    • /
    • 제8권1호
    • /
    • pp.23-30
    • /
    • 1994
  • This study discusses the wave transformation(wave reflection and transmission) by a impermeable submerged breakwater with one ray, and integrated horizontal wave pressure acting on the structure. Numerical method in this study is based on the simplified eigenfunction expansion method and linear wave theory. Although this method is very simple, the results give good agreement with the one of the strict eigenfunciton expansion method, especially, in case that the crown width of the submerged breakwater becomes longer and its crown water depth shallower. Therefore, it is concluded that this simplified method is one good method in planning coastal structures as like the submerged breakwater in this study, and computing their wave transformations.

  • PDF

제3세대 파랑모델의 비선형 에너지 이송항 계산 효율 증대를 위한 SRIAM 계산모듈 개발 (Development of SRIAM Computation Module for Enhanced Calculation of Nonlinear Energy Transfer in 3rd Generation Wave Models)

  • 이주용;윤재선;하태민
    • 한국해양공학회지
    • /
    • 제31권6호
    • /
    • pp.405-412
    • /
    • 2017
  • Because of the rapid development of computer technology in recent years, wave models can utilize parallel calculations for the high-resolution prediction of open sea and coastal areas with high accuracy. Parallel calculations also allow national agencies in the relevant sectors to produce marine forecasting data through massive parallel calculations. Meanwhile, the eastern coast of the Korean Peninsula has been increasingly damaged by swell-like high waves, and many researchers and scientists are continuing their efforts to anticipate and reduce the damage. In general, the short-term transformation of swell-like high waves can be reproduced relatively well in the third generation wave models, but the transformation of relatively long period waves needs to be simulated with higher accuracy in terms of the nonlinear wave interactions to gain a better understanding of the low-frequency wave generation and development mechanisms. In this study, we developed a calculation module to improve the calculation of the nonlinear energy transfer in the 3rd generation wave model and integrated it into the wave model to effectively consider the nonlinear wave interaction. First, the nonlinear energy transfer calculation module and third generation model were combined. Then, the combined model was used to reproduce the wave transformation due to the nonlinear interaction, and the performance of the developed operation module was verified.

산란체법에 의한 다중 계단지형에서의 파랑변형 계산 (Computation of Wave Transformation over a Multi-Step Topography by a Scatterer Method)

  • 서승남
    • 한국해안·해양공학회논문집
    • /
    • 제20권5호
    • /
    • pp.439-451
    • /
    • 2008
  • 단일 계단지형에 대한 반사파와 투과파의 해를 이용하여 다중 계단지형에서의 파랑변형을 계산할 수 있는 새로운 산란체법의 모형을 구성하였다. 산란체법의 근사해를 보다 정밀한 Kirby and Dalrymple(1983)이 제시한 EFEM의 해와 비교검증하였다. 진행파만의 근사에서는 산란체법과 EFEM의 해는 동일하다. 계산된 반사율과 투과율에 대한 위상의 경우 억류파를 포함한 산란체법의 해는 진행파만의 근사해보다 훨씬 우수하다. 억류파의 영향이 감소할수록 산란체법의 해는 EFEM의 해로 접근한다.

단일계단 지형에서 변분근사법과 고유함수 전개법에 의한 파랑변형 비교 (Comparison between Variational Approximation and Eigenfunction Expansion Method for Wave Transformation over a Step Bottom)

  • 서승남
    • 한국해안·해양공학회논문집
    • /
    • 제21권2호
    • /
    • pp.91-107
    • /
    • 2009
  • 단일 계단지형 위를 지나는 선형 파랑의 변형을 계산하기 위해 변분근사법과 고유함수 전개법을 사용하였다. 이들 수치해를 비교에서 반사율과 투과율 그리고 해면변위는 거의 일치한다. 그러나 계단 경계에서 유속 정합조건이 부여되었음에도 불구하고 계산된 x방향 유속의 수직구조는 차이를 보인다.

타원형 수중천퇴상의 규칙파 및 불규칙파의 전파변형 실험(I):비쇄파조건 (Experiments for Wave Transformation of Regular and Irregular Waves over a Submerged Elliptic Shoal(I) : Non-breaking Conditions)

  • 이종인;이정욱
    • 한국해안해양공학회지
    • /
    • 제14권3호
    • /
    • pp.240-246
    • /
    • 2002
  • 타원형 천퇴해역에 대한 규칙파 및 일방향 불규칙파의 전파변형에 대한 수리모형실험을 수행하였다. 수리모형실험은 비쇄파조건의 규칙파와 천퇴의 정상부에서 부분쇄파가 발생하는 일방향 불규칙파를 대상으로 수행되었다. 수리모형실험 조건에 대해 포물형근사식을 적용한 수치해석을 수행하여 실험결과와 비교하였다.

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

  • 윤종태
    • 한국해양공학회지
    • /
    • 제18권4호
    • /
    • pp.40-45
    • /
    • 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.

Wave propagation of graphene platelets reinforced metal foams circular plates

  • Lei-Lei Gan;Jia-Qin Xu;Gui-Lin She
    • Structural Engineering and Mechanics
    • /
    • 제85권5호
    • /
    • pp.645-654
    • /
    • 2023
  • Based on first-order shear deformation theory, a wave propagation model of graphene platelets reinforced metal foams (GPLRMFs) circular plates is built in this paper. The expressions of phase-/group- velocities and wave number are obtained by using Laplace integral transformation and Hankel integral transformation. The effects of GPLs pattern, foams distribution, GPLs weight fraction and foam coefficient on the phase and group velocity of GPLRMFs circular plates are discussed in detail. It can be inferred that GPLs distribution have great impacts on the wave propagation problems, and Porosity-I type distribution has the largest phase velocity and group velocity, followed by Porosity-III, and finally Porosity-II; With the increase of the GPLs weight fraction, the phase- and group- velocities for the GPLRMFs circular plate will be increased; With the increase of the foam coefficient, the phase- and group- velocities for the GPLRMFs circular plate will be decreased.