• Title/Summary/Keyword: Run up

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Numerical Study on Wave Run-up of a Circular Cylinder with Various Diffraction Parameters and Body Drafts

  • Jeong, Ho-Jin;Koo, Weoncheol;Kim, Sung-Jae
    • Journal of Ocean Engineering and Technology
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    • v.34 no.4
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    • pp.245-252
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    • 2020
  • Wave run-up is an important phenomenon that should be considered in ocean structure design. In this study, the wave run-up of a surface-piercing circular cylinder was calculated in the time domain using the three-dimensional linear and fully nonlinear numerical wave tank (NWT) techniques. The NWT was based on the boundary element method and the mixed Eulerian and Lagrangian method. Stokes second-order waves were applied to evaluate the effect of the nonlinear waves on wave run-up, and an artificial damping zone was adopted to reduce the amount of reflected and re-reflected waves from the sidewall of the NWT. Parametric studies were conducted to determine the effect of wavelength, wave steepness, and the draft of the cylinder on the wave run-up of the cylinder. The maximum wave run-up value occurred at 0°, which was in front of the cylinder, and the minimum value occurred near the circumferential angle of 135°. As the diffraction parameter increased, the wave run-up increased up to 1.7 times the wave height. Furthermore, the wave run-up was 4% higher than the linear wave when the wave steepness was 1/35. In particular, the crest height of the wave run-up increased by 8%.

Frequency analysis of wave run-up on vertical cylinder in transitional water depth

  • Deng, Yanfei;Yang, Jianmin;Xiao, Longfei;Shen, Yugao
    • Ocean Systems Engineering
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    • v.4 no.3
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    • pp.201-213
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    • 2014
  • Wave run-up is an important issue in offshore engineering, which is tightly related to the loads on the marine structures. In this study, a series of physical experiments have been performed to investigate the wave run-up around a vertical cylinder in transitional water depth. The wave run-ups of regular waves, irregular waves and focused waves have been presented and the characteristics in frequency domain have been investigated with the FFT and wavelet transform methods. This study focuses on the nonlinear features of the wave run-up and the interaction between the wave run-up and the cylinder. The results show that the nonlinear interaction between the waves and the structures might result wave run-up components of higher frequencies. The wave run-ups of the moderate irregular waves exhibit 2nd order nonlinear characteristics. For the focused waves, the incident waves are of strong nonlinearity and the wavelet coherence analysis reveals that the wave run-up at focal moment contains combined contributions from almost all the frequency components of the focused wave sequence and the contributions of frequency components up to 4th order harmonic levels are recommended to be included.

Analytical Rapid Prediction of Tsunami Run-up Heights: Application to 2010 Chilean Tsunami

  • Choi, Byung Ho;Kim, Kyeong Ok;Yuk, Jin-Hee;Kaistrenko, Victor;Pelinovsky, Efim
    • Ocean and Polar Research
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    • v.37 no.1
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    • pp.1-9
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    • 2015
  • An approach based on the combined use of a 2D shallow water model and analytical 1D long wave run-up theory is proposed which facilitates the forecasting of tsunami run-up heights in a more rapid way, compared with the statistical or empirical run-up ratio method or resorting to complicated coastal inundation models. Its application is advantageous for long-term tsunami predictions based on the modeling of many prognostic tsunami scenarios. The modeling of the Chilean tsunami on February 27, 2010 has been performed, and the estimations of run-up heights are found to be in good agreement with available observations.

Simulating three dimensional wave run-up over breakwaters covered by antifer units

  • Najafi-Jilani, A.;Niri, M. Zakiri;Naderi, Nader
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.2
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    • pp.297-306
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    • 2014
  • The paper presents the numerical analysis of wave run-up over rubble-mound breakwaters covered by antifer units using a technique integrating Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) software. Direct application of Navier-Stokes equations within armour blocks, is used to provide a more reliable approach to simulate wave run-up over breakwaters. A well-tested Reynolds-averaged Navier-Stokes (RANS) Volume of Fluid (VOF) code (Flow-3D) was adopted for CFD computations. The computed results were compared with experimental data to check the validity of the model. Numerical results showed that the direct three dimensional (3D) simulation method can deliver accurate results for wave run-up over rubble mound breakwaters. The results showed that the placement pattern of antifer units had a great impact on values of wave run-up so that by changing the placement pattern from regular to double pyramid can reduce the wave run-up by approximately 30%. Analysis was done to investigate the influences of surface roughness, energy dissipation in the pores of the armour layer and reduced wave run-up due to inflow into the armour and stone layer.

Effect of hydraulic and structural parameters on the wave run-up over the berm breakwaters

  • Milanian, Farzad;Niri, Mahmood Zakeri;Najafi-Jilani, Ataollah
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.3
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    • pp.282-291
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    • 2017
  • The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged Navier-Stokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

Experimental study on Run-up of S-berm-Typed Rubble Mound Breakwaters (S-소단 경사식 방파제에서의 처오름에 대한 실험연구)

  • Ahn, Tae-Jun;Park, Seung-Hyuun;Jang, Won-Jae;Cho, Yong-Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1919-1924
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    • 2006
  • In this study, the run-up of water waves on slopes of s-berm breakwaters was investigated by performing a series of hydraulic experiments. The run-up height was analyzed in detail by using the effects of wave steepness and surf similarity parameter. In general, the run-up heights were decreased as the height and the width of berm were increased. However, the variation of run-up height was small for change of wave steepness and surf similarity parameter.

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Experimental Study for Hydraulic Characteristics as the Permeable Underlayer Thickness of Rubble mound Structure (사석방파제 투수하부층 두께에 따른 사면상의 수리특성 실험연구)

  • 윤한삼;김종욱;류청로
    • Journal of Ocean Engineering and Technology
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    • v.16 no.3
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    • pp.40-45
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    • 2002
  • In this study, the effects on hydraulic characteristics are discussed as the permeable underlayer thickness of the rubble mound structure changes. A series of hydraulic experiments were performed and wave run-up, reflection and set-up were investigated. Result indicated that wave run-down was affected by the water out from the permeable underlayer during down-rush. As the thickness increased, relative wave run-up decreased.

Run-up of Cnoidal Waves on Steep Slopes (급경사에서 크노이드파의 처오름)

  • 조용식;윤태훈
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.1
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    • pp.44-51
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    • 1996
  • The accurate calculation of run-up heights of long waves along the coastline is important in the view of engineering. In this paper the run-up heights of long waves are estimated by using the cnoidal wave theory which also covers both sinusoidal and solitary waves. However, the generation and the calculation of run-up heights of cnoidal waves are difficult both in laboratory and numerical experiments. In this study, the maximum run-up heights of cnoidal waves on steep slopes are computed by using the boundary integral equation model. It has been shown that the run-up heights of cnoidal waves are less than those of solitary waves, while they are larger than those of sinusoidal waves having the same wavelengths and heights. The variation of run-up heights of cnoidal waves is not a monotonic function of the wavelength. However, the run-up heights of cnoidal waves asymptotically approach that of a solitary wave as the wavelength approaches infinity. The calculated run-up heights agreed reasonably with experimental data.

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Wave Run-up Characteristics of Ocean Wave, Current, and Kelvin Wave Interaction in the Canal (운하에서 파랑·흐름·항주파의 상호작용에 의한 처오름 특성)

  • Hur, Dong-Soo;Lee, Woo-Dong;Jung, Kwang Hyo
    • Journal of Ocean Engineering and Technology
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    • v.27 no.4
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    • pp.55-61
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    • 2013
  • The numerical simulation using LES-WASS-3D is developed to investigate the wave run-up on the revetment along the canal. Interaction of ocean wave, current, and Kelvin wave is investigated on 40 conditions varying the number of ship, cruising direction, and relative cruising location of ships, when a 650TEU container cruises in the canal. The mean wave run-up heights on the revetment are compared for every simulated conditions. The largest height of wave run-up is generated at the C-pair condition and the wave run-up generated at the canal entrance is larger than that at the inside canal. When Kelvin waves is interacted with the current, the mean wave run-up height is increased approximate 10% compared with no current condition.

A study of the noise suppression system at the aircraft ground run-up test room (항공기 지상실험에 의한 소음 저감 방안에 관한 연구)

  • 김인수;고철수;김형근
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.718-723
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    • 2003
  • The number of jet aircraft is increasing. The aircraft noise making people near airports nervous have become a serious social problem. The aircraft noise can be classified into two groups; noise being generated at take-off or landing and noise form run-up test on the ground. In this paper, we consider the aircraft noise from run-up test on the pound and we suggest the noise suppression system.

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