• 한국해양공학회지
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• 제25권6호
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• pp.23-28
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• 2011

In this paper, a new generation method for ship induced waves is proposed using the fully non-linear 3-D numerical model with non-reflected wave generation system (LES-WASS-3D). A ship induced wave generated by the newly proposed method is examined in comparison with that obtained by an empirical formula. It is then shown that there is a good agreement in free surface the elevation between them. As a result, it is revealed that a ship induced wave in a 3-D numerical wave field can be simulated well using LES-WASS-3D.

• 대한토목학회논문집
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• 제31권3B호
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• pp.305-308
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• 2011

본 연구에서는 무반사 조파시스템을 적용한 3차원 수치파동수조에서 다양한 다방향불규칙파의 조파 방법에 의한 다방향불규칙파의 방향분포함수에 대해서 검토하였다. 그 결과 무반사 조파가 가능한 3차원 수치파동수조(LES-WASS-3D)에서 다방향불규칙파의 조파가 가능한 것을 확인하였다.

• 한국해안·해양공학회논문집
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• 제23권6호
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• pp.401-406
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• 2011

본 연구에서는 3차원 수치파동수조에서 무반사 조파시스템을 이용한 경사입사파의 조파방법을 새롭게 제안하고, 계산된 수면변위 및 수평유속에 대한 수치결과와 Stokes파의 3차 근사이론값과의 비교 분석을 통하여 새로운 모델의 검증을 실시하였다. 그 결과 본 연구에서 제안한 경사입사파의 조파방법의 타당성과 유효성을 확인할 수 있었다.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2009년도 발표 논문집 제18권
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• pp.224-227
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• 2009

• 한국해양공학회지
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• 제26권2호
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• pp.68-78
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• 2012

This study proposes an improved 3-D model that includes a new non-reflected wave generation system for oblique incident and multi-directional random waves, which enables us to estimate the effect of the various wave-types on 3-D wave fields in a coastal area with permeable submerged breakwaters. Then, using the numerical results,the three-dimensional wave field characteristics around permeable submerged breakwaters are examined in cases of oblique incident and multi-directional random waves. Especially, the wave height, mean surface elevation and mean flow around the submerged breakwaters are discussed in relation to the variation of incident wave condition.

• 한국해양공학회지
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• 제33권4호
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• pp.364-376
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• 2019

When underwater blasting is conducted, both shock waves and water waves have an effect on adjacent coastal areas. In this study, an empirical formula for estimating the details of water waves caused by underwater blasting was applied to a non-reflected wave generation system, and a 3D numerical wave tank (NWT) was improved to reproduce the generation and propagation of such water waves. The maximum elevations of the propagated water waves were comparatively analyzed to determine the validity and effectiveness of the NWT. Good agreement was demonstrated between the empirical and simulation results. The generation and propagation of water waves were also simulated under each underwater blasting scenario for the removal of the Todo islet at the Busan Newport International Terminal (PNIT). It was determined that the water waves generated by the underwater blasting scenario examined in this study did not have a significant impact on the PNIT. In addition, multiple-charge blasting caused higher wave heights than single-charge blasting. As the amount of firing charge increased, the wave height also increased. Finally, larger water waves were generated during the later blasting conducted at a deeper depth as compared with an earlier blasting conducted at a relatively shallow depth.

• 한국해양공학회지
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• 제31권2호
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• pp.121-129
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• 2017

The present study numerically investigated the influence of the waveform distribution on the tsunami-vegetation interaction using a non-reflected wave generation system for various tsunami waveforms in a two-dimensional numerical wave tank. First, it was possible to determine the wave attenuation mechanism due to the tsunami-vegetation interaction from the spatial waveform, flow field, vorticity field, and wave height distribution. The combination of fluid resistance in the vegetation and a large gap and creates a vortex according to the flow velocity difference in and out of the vegetation zone. Thus, the energy of a tsunami was increasingly reduced, resulting in a gradual reduction in wave height. Compared to existing approximation theories, the double volumetric ratio of the waveform increased the reflection coefficient of the tsunami-vegetation interaction by 34%, while decreasing the transfer coefficient and energy attenuation coefficient by 25% and 13%, respectively. Therefore, the hydraulic characteristics of a tsunami is highly likely to be underestimated if the solitary wave of the approximation theory is applied for the tsunami.

• 한국해양공학회지
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• 제33권1호
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• pp.76-84
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• 2019

For decades, solitary waves have commonly been used to simulate tsunami conditions in numerical studies. However, the main component of a tsunami waveform acts at completely different spatial and temporal distributions than a solitary waveform. Thus, this study applied a 2-D numerical wave tank that included a non-reflected tsunami generation system based on Navier-Stokes equations (LES-WASS-2D) to directly simulate the run-up of a tsunami-like solitary wave on a slope. First, the waveform and velocity due to the virtual depth factor were applied to the numerical wave tank to generate a tsunami, which made it possible to generate the wide waveform of a tsunami, which was not reproduced with the existing solitary wave approximation theory. Then, to validate the applied numerical model, the validity and effectiveness of the numerical wave tank were verified by comparing the results with the results of a laboratory experiment on a tsunami run-up on a smooth impermeable 1:19.85 slope. Using the numerical results, the run-up characteristics due to a tsunami-like solitary wave on an impermeable slope were also discussed in relation to the volume ratio. The maximum run-up heights increased with the ratio of the tsunami waveform. Therefore, the tsunami run-up is highly likely to be underestimated compared to a real tsunami if the solitary wave of the approximation theory is applied in a tsunami simulation in a coastal region.

• 한국수자원학회논문집
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• 제51권8호
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• pp.643-654
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• 2018

수치파동수조에서 안정적인 지진해일을 조파하기 위하여 2차원 수치모델(LES-WASS-2D)에 다양한 파형의 지진해일을 고려할 수 있는 무반사 조파시스템을 도입하였다. 기존 실험에서 측정한 호안주변의 지진해일의 시 공간 파형들과 비교하여 수치계산결과가 높은 정확도를 나타내었다. 이로써 본 연구에서 적용한 수치모델이 지진해일 월파모의에 있어서 적합하다는 것을 보여주었다. 지진해일 월파모의결과로부터 지진해일 체적비와 파고와 수심비에 따른 월퍄량, 침수거리를 고찰하였다. 지진해일의 파형이 넓을수록 월파량이 선형적으로 증가하였으며, 침수거리 또한 증가하였다. 그러므로 고립파 근사이론을 지진해일의 월파 및 침수모의에 적용할 경우, 실제 지진해일보다 수리특성이 과소평가 될 우려가 크다.