Drift Motion Analysis on Horizontal Plane of a Two-Point Moored Oil Tanker

J. Ocean Eng. Technol. 2004;18(3):8-12.

2점 계류된 선박에 대한 수평면상 표류운동 해석

이호영,임춘규

목포대학교 선박해양시스템 공학과,현대미포조선(주)

Keywords: 3-Dimensional Panel Method, Two Point Mooring System, Slow Maneuvering Equation, Wind Spectrum, Slow Drift Motion

핵심용어: 3차원 패널법, 2점 계류 장치, 저속 조종 운동방정식, 바람 스펙트럼, 저속 표류운동

Abstract

The anchor is laid on the seabed, and the main engine is working against incident environmental loads in a typhoon. As the main engine is broken Mum in the storm, the anchor chain is cut and the vessel drifts. Although a ship is moored by two-point mooring lines to maintain her position, it has crashed into a rock because of a typhoon, resulting in a possible accidental oil spillage. In this paper, we studied maintenance of a ship's position, which is analyzed based on the slow motion maneuvering equations considering wave, current, and wind. To estimate wave loads, the direct integration method is employed. The current forces are calculated, using MMG (Mathematical Modeling Group). Th two-point mooring forces are quasi-statistically evaluated, using the catenary equation. Th coefficients of wind forces are modeled from Isherwood's empirical data, and the variation of wind speed is estimated by wind spectrum. The nonlinear motions of a two-point moored ship are simulated, considering wave, current, and wind load, in specific domain of time.