Variations of water particle kinematics of offshore tlps with perforated members: numerical investigations

Offshore Tension Leg Platforms (TLP) are often subjected to criticalenvironmental loads that cause serious damage; MARS TLP in GoM, damaged byhurricane Katrina in 2005 is an example. Existence of external perforated coverreduces hydrodynamic forces on the existing members caused by direct waveimpact. Although many studies confirm this fact but variations in the water particlekinematics along the water depth needs a detailed investigation to verify the phenomenon.Geometric configuration of the column member of the damaged MARStension leg platform (TLP) is modeled on a 1:100 scale with an external perforatedcover. Variations of water particle kinematics of the column member, encompassedby perforated cover are presented through detailed CFD analysis. Traces of the horizontal water particle velocity along the water depth are derived for a wide rangeof wave period under the critical wave amplitude. Results of the numerical studiesshow that there is a significant reduction in the water particle velocity, whichverifies the fact of reduction in forces on the column members. The attempted studycan be seen as a prime-facie to investigate the retrofitting and rehabilitation processof the damaged TLP.