Study On Hydrodynamics Analysis Of Tension Leg Platform

The tension-leg platform (TLP) is a hybrid type of offshore platform, fixed for the verti-cal degrees of freedom and compliant for the horizontal degrees of freedom. The platform structure is connected to the sea-bed template by tendons (tension legs) which are kept in ten-sion under all conditions by the excess buoyancy over weight of the platform. In this paper several types of TLP are compared with their different backgrounds, structural features.It is very important to do hydrodynamic analysis for TLP in their basic design phase. Re-sponse amplitude operators (RAO) can be obtained in the hydrodynamic analysis, being a sta-tistical measurement of different response under different wave directions and wave periods. Based on the three dimensional potential theory, this paper did the theoretical and numerical hydrodynamic analysis of a traditional TLP to evaluate its global performance. DNV/SESAM software is used to do the modeling and calculating work. Totally four models were built, Panel model, Morison model, Mass model, and Geometry model. TLP added mass and poten-tial damping matrix are calculated, and first and second order wave forces are displayed with reference to different wave directions and periods.Based on the above work, further analysis is made about factor sensitivity study, includ-ing water depth, draft, and tendon numbers. In this frequency domain analysis water depth and tendon numbers can be significant parameter to the global performance of TLP.Assuming stationary Gaussian incoming waves and a narrow banded response spectrum, the response amplitudes are Rayleigh distributed. In order to investigate the vessel motion and load conditions in a short period like few minutes or hours, short-term statistics are analysis to give out the extreme values of motions or loads in this period.