THE EFFECT OF MOONPOOL AND DAMPING PLATE ON DAMPING CHARACTERISTICS OF SPAR HULLS USING CFD SIMULATION

摘要

Spar platforms used in offshore industry, commonly have moonpool at the centre to accommodate risers and conductorsrn(wells). In order to keep the heave response within an acceptable limits, heave damping plates have also been introduced inrnsome cases. While the research on damping and response characteristics of Spar hulls have been progressing over the last tworndecades, the literature on the moonpool effect and damping plate is limited, in experimental and computational fluid dynamicsrn(CFD). The present work is a comparative study of heave and pitch damping characteristics of three Spar hull configurations:rn(1) Classic Spar and (2) Classic Spar with moonpool (3) Classic Spar with moonpool and damping plate. Free decay tests arerncarried out in a wave flume of 2 m water depth. The experimental results exhibit an increase in heave damping for spar modelrnwith moonpool. This may be due to the sloshing effects inside the moonpool. The pitch damping is not significantly alteredrndue to the addition of moonpool. The addition of damping plate further increases the heave and pitch damping. CFDrnsimulations for the same has been carried out in a numerical wave tank using commercial software Star-CCM+, which isrncapable of establishing the viscous effects for floating bodies. The numerical investigations further substantiated the findingsrnof the experiment.