Design Selection Analysis for Mooring Positioning System of Deepwater Semi-submersible Platform

摘要

Aiming at design selection analysis for mooring positioning system of asemi-submersible platform applied in South China Sea, catenarymooring system, semi-taut mooring system and taut mooring systemare respectively considered. The three types of mooring positioningsystem have the similar static restoring force characteristics, the samemooring line number and angle arrangement. The dynamic couplingeffects between the semi-submersible platform and its mooring linesare investigated through numerical simulation method. The 3-dimension hydrodynamic finite element model of semi-submersibleplatform is built firstly. The wave forces are calculated underdiffraction theory by boundary element method, and the wind forces areobtained from the wind tunnel test with the model scale 1:100, and thecurrent forces are considered as steady. The platform motions undercombined action of wind, wave and current are solved by Runge-Kuttamethod respectively under working and extreme conditions in SouthChina Sea. The specific numerical results and analysis conclusionswould be helpful for selecting the mooring system and the motionperformance study in the semi-submersible platform preliminary design.