Reduction of Pitch Motion of FPSO Vessels by Innovative OWC Passive Control Available to Purchase

The improvement of the seakeeping capabilities of Floating, Production, Storage and Offloading (FPSO) vessels increases safety and allows its operation on severe weather conditions. It also increases the fatigue life of the risers. Hence, any improvement on the FPSO motion is mostly welcome. Guimarães [1], following similar efforts by Silva [2], studied the reduction of pitch motions of FPSO vessels with the use of the OWCs (Oscillating Water Columns) passive system. However, both experimental and numerical results were inconclusive due to green water effects during experiments and panel issues with the panel code WAMIT [3], respectively. The objective of the present work is to report a series of new tests that prove the feasibility of an “L-shaped” moon pool concept and estimates and tests the ideal length of such concept that maximizes the restoring moment and minimizes pitch the most. The tests were conducted in the Laboratório de Ondas e Correntes (Laboratory of Waves and Currents) of the Federal University of Rio de Janeiro (COPPE/UFRJ).