• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3B
• /
• pp.307-313
• /
• 2008

Tidal amplification by construction of sea-dike and sea-walls had been detected not only near Mokpo North Harbor but also at Chungkye Bay which is connected with Mokpo North Harbor by a narrow channel. This brings about increase of tidal flat area and in particular increase of runup height and inundation area during storms. In this study, a simulation process is composed of wind wave generation model for large area and wave inundation model for small coastal zone. The nonlinear version of mild-slope equation is modified for simulating wind-driven surge and wave inundation at a small area. The models are applied to Chungkye Bay, and possible inundation features at Mokpo North Harbor are investigated.

• Journal of KIISE
• /
• v.42 no.7
• /
• pp.846-851
• /
• 2015

Seas and swells are basic wave types in ocean surface simulation and are very important elements in the simulation of ocean background. In this paper, we propose a real-time simulation method, for reproducing realistic seas and swells, to be used in real-time simulators such as ship maneuvering simulators. Seas and swells have different visual properties. Swells have relatively longer wavelengths and round crests compared with seas, therefore they are visualized globally with large meshes and procedural methods. Parameters to illustrate swells are extracted from ocean wave spectra. Conversely, seas have shorter wavelengths and their characteristics are only clearly apparent near to the observation point. Here, we present visualization of seas based on a statistical wave model using ocean wave spectra, which provides realistic results in a reactively small area.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.12 no.1
• /
• pp.39-52
• /
• 2000

The triad interactions have been known to be important only for shoaling waves or finite depth wind waves. In deep water, they are insignificant compared with the quadruplet interactions in respect to the evolution of wind waves due to energy transfer among the wave components. However, the triad interactions may be important even for deep water waves because they may closely be related to the wave steepness, which definitely affects wave breaking, drag of air flow over t.'Ie sea, or navigation of ships, especially during the early stage of the development of wind waves. This study reports a series of laboratory experiments, whose data are subjected to bispectral analyses to investigate the triad interactions of deep-water wind waves. It is found that the bicoherence at the spectral peak frequency and the wave steepness are almost directly proportional, indicating that the steep waves with peaked crests and flat troughs are resulted from the triad interactions. Both bicoherence and wave steepness increase with the wave age during the early stage of wave generation and then drop off as the waves grow old. It seems that the energy of the secondary spectral peak developed by the triad interactions during the early stage of wave generation is redistributed to the neighboring frequencies by the quadruplet interactions during the later stage.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
• /
• 1996.10a
• /
• pp.38-41
• /
• 1996

심해에서 풍파의 형성은 주로 바람에 의한 마찰력과 파와 파간의 상호간섭 그리고 white capping 현상등에 의한 1차 에너지 손실에 의하여 이루어지며, 파의 변이는 주로 이상의 세 가지 물리현상에 좌우된다. 이러한 심해역에서의 파의 변이를 해석할 때 굴절, 회절 및 마찰손실 등에 의한 천해역 현상은 무시할 수 있으며 풍파의 형성은 주로 바람 조건에 좌우된다. 그러나 파도가 일단 심해역에서 천해역으로 들어오게 되면, 천수, 굴절, 회절 및 마찰손실 등에 의하여 급격하게 변이한다. (중략)

• 한국해양학회지
• /
• v.19 no.2
• /
• pp.195-199
• /
• 1984

Effect of drift current on the first stage of wave generation by wind is studied theoretically. The viewpoint is similar to the one described by Phillips (1957) except that drift current is considered. It is found that inclusion of the effect of the drift current modifies significantly the results obtained by Phillips, particularly the resonance condition and wave spectrum.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2018.11a
• /
• pp.55-56
• /
• 2018

대규모 해군 사업인 장보고-III 시설사업의 간략한 사업개요와 공사시 또는 완공후의 원활한 시설운용을 위한 파고예측시스템을 개발 및 적용하였다. 진해만의 지리적 특성을 고려하여 풍파가 주요파라메타로 설정하였으며, 인근 기상대 바람예보 자료를 활용하여 주요지점에 대해 파고를 예측할 수 있는 시스템을 개발하였으며, 향후 공사시 활용할 수 있다. 또한, 특정사업 및 특정 지역에 대한 간략 파고예측시스템의 제작으로 시공 및 현장에 유익한 정보 전달이 가능하다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.19 no.1
• /
• pp.16-28
• /
• 2007

The results of experimental investigation of coherent structures beneath wind-generated waves in deep water are presented. Vorticity fields of deepwater wind waves were visualized by analyzing the velocity fields obtained by PIV measurements under different wind and fetch conditions. In addition, spatio-temporal evolution of the coherent structures and subsequent changes in vertical profiles of the instantaneous vorticity were qualitatively examined. It was found that a coherent structure is formed right underneath the wave crest and traveled in phase with the surface wave. The direction of rotation of the coherent structure was contrary to the wave orbital motion when wind speed is less than 10 m/s, while was same as the wave orbital motion when wind speed is approximately 13 m/s and wave breaking occurs at the wave crest. In the near-surface region, complex vortex-vortex interactions were observed according to the traveling of the coherent structure. In contrast, coherent structures far below the water surface changed little due to weak influence of orbital motion by the surface waves.

• Water for future
• /
• v.45 no.12
• /
• pp.63-71
• /
• 2012

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.16 no.3
• /
• pp.178-189
• /
• 2004

For designing a reliable harbor, a methodology for estimating design waves of 97.5% operable harbor condition is suggested using long-term wave data. For a practical application of the methodology, a marine police harbor was selected as a site. Wave data used were collected from February 1993 to December 2003 at Jodo wave gage station in front of Pusan harbor. Joint distributions of significant wave height and significant wave period for specified wave directions were obtained and used to feed as input waves for parabolic mild-slope wave model. Results showed that input waves with significant wave height of 1.75 m, significant wave period off sec and wave direction E yield design waves height of 1.06 m at the site of interests, which is a 97.5% operable harbor condition. Wind waves generated inside harbor showed to be no effect on the design wave condition. Swells propagated from deep water into harbor are shown to be dominant effects on the design waves of operable harbor condition.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.2
• /
• pp.101-111
• /
• 2010

Characteristics of large-height swell-like waves that repeatedly occurred on the Korean East Coast in winter season were analyzed by using the wave observation data and the meteorological data. Based on the results of the data analysis, it was demonstrated that the swell-like waves have been generated due to the long-lasting strong northeasters in the East Sea, which were formed as a result of the low pressure trough in the vicinity of the extratropical low pressure system that advanced to East Sea from the China inland with decreasing its central pressure. Among the recently occurred events of the swell-like waves, the characteristics of the two events in October 2005 and 2006 were predominantly wind waves. Meanwhile, the one in February 2008 seems to be occurred by the initial wave growth due to wind waves followed by the secondly increase of the wave height due to longer-period swell.