An Analysis of Rolling Performance for a Barge-Type FPSO

J. Ocean Eng. Technol. 2005;19(3):25-30.

Choi Yoon-Rak,Kim Jin-Ha,Kim Young-Su

School of Transportation Systems Engineering University of Ulsan,Korea Research Institute of Ships and Ocean Engineering KORDI,Ship and Ocean R&D Institute Daewoo Shipbuilding & Marine Engineering Co. Ltd.

바아지형 FPSO의 횡운동 성능에 대한 해석

최윤락,김진하,김용수

울산대학교 조선해양공학부,한국해양연구원 해양시스템안전연구소,대우조선해양(주) 선박해양기술연구소

Keywords: Free Roll Decay Test, Quadratic Damping, Wideband Wave Spectrum, Equivalent Linear Damping

핵심용어: 횡운동 자유감쇠시험, 2차항 감쇠, 광대역 파랑스펙트럼, 등가선형감쇠

Abstract

To predict rolling performance for a barge-type FPSO, the evaluation of correct nonlinear roll damping is critical. The square section of FPSO causes a considerable viscous damping effect. Free roll decay tests were carried out to estimate nonlinear roll damping for a barge-type FPSO, under three different conditions. The roll motion RAO was deduced from model tests in the wave condition of the wideband spectrum. In numerical calculation, the quadratic damping was considered as equivalent linear damping, using the results of free roll decay test. Tested roll performance in the JONSWAP wave spectrum was compared with numerical results. These two results shaw good agreement, in spite of the proximity of peak wave period and roll natural period.