Young-Gill Lee

Numerical simulation of the free surface around a circular column in regular waves using modified marker-density method

Abstract In this paper the wave run-up around a circular column in regular waves is numerically calculated to investigate the applicability of the Modified Marker-Density (MMD) method to prediction of wave run-up around an offshore platform. The MMD method is one of the methods to define the highly nonlinear free surface. The governing equations are the Navier-Stokes equations and the continuity equation which are computed in Cartesian grid system. To validate incident waves generated by numerical simulation, those are compared with the solutions of the Stokes 5th order wave theory. The wave run-up simulations are performed varying the steepness and period of incident waves as referred experimental data. The numerical results are compared to the experimental data and the results show good agreements.

HULL FORM DESIGN OF A PASSENGER CATAMARAN FOR OPERATION IN THE YELLOW SEA REGION

The Yellow Sea between the Korean peninsula and northeast China possesses a strong hinterland composed of major industrial complexes and cities of neighboring countries. With the recent economic growth of the countries, trade volume in the Yellow Sea region has seen a rapid increase and therefore necessitates an introduction of efficient and integrated logistics systems for the region. Incheon Metropolitan City is a geographical center of the Yellow Sea region as well as the sea and air gateway to the Korean capital area. This paper presents how a passenger catamaran has been planned to meet economical and natural requirements for operation in the city. Hull forms of the catamaran and their resistance characteristics in both deep and shallow waters are studied using model experiments and numerical simulations to determine practical applicability.

Study on the Development of Removing System for Waterbed Sediment by the Difference of Water Head

AbstractAccording to the existing research result on the seabed organic sediment, pollutants from the land and the sea contaminate the coastal water and sediment on the seabed. To tackle this problem, we need to dredge organic sediment. In the presen t paper, the development of removing system of seabed sediment by the difference of water head is researched by experimental method. For the validation of the decompression system, computations for validation are carried out for sediment removing equipment. The performance of inhalation equipment is analysed by some model tests. ※Keywords: Water head(수두), decompression(감압), Inhalation equipment(흡입장비), Sediment(퇴적물), Model test(모형시험) 1. 서론 연안 해역 특히 음식점과 어시장이 들어서 있는 어항 내에서는 생선 세척수와 어패류 사체로 오염 접수일: 2006년 12월 29일, 승인일: 2008년 1월 28일✝교신저자: younglee@inha.ac.kr, 032-860-7340 은 점점 심해지고 있다. 해저 유기퇴적물에 관한 기존의 연구결과에 의하면 육상과 해상에서 유입된 오염물이 연안 해역에 퇴적되어 수온상승과 무산소환경의 확산으로 인해 적조현상의 주원인인 인(P)성분이 다량 용출되는 것으로 밝혀졌다(Hakanson and Jansson 1983, Lee and Lee 2004, Lennox 1984). 이를 개선하기 위해서는 해