Investigation of Safety and Design of Mooring Lines for Floating Wave Energy Conversion

doi:2012.26.4.77

J. Ocean Eng. Technol. > Volume 26(4); 2012 > Article

J. Ocean Eng. Technol. 2012;26(4):77-85.
DOI: https://doi.org/10.5574/KSOE.2012.26.4.077

Jung Dong-Ho,Nam Bo-Woo,Shin Seung-Ho,Kim Hyeon-Ju,Lee Ho-Saeng,Moon Deok-Soo,Song Je-Ha

Maritime and Ocean Engineering Research Institute KORDI,Maritime and Ocean Engineering Research Institute KORDI,Maritime and Ocean Engineering Research Institute KORDI,Maritime and Ocean Engineering Research Institute KORDI,Maritime and Ocean Engineer

부유식 파력발전장치용 계류선의 설계 및 안전성 검토에 관한 연구

정동호,남보우,신승호,김현주,이호생,문덕수,송제하

한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소,한국해양과학기술원 선박해양플랜트연구소

Keywords: Mooring line, Design, Extreme value analysis, Pretension, Safety analysis

핵심용어: 계류선, 설계, 극한해석, 초기장력, 안전성해석

Abstract

A study was performed on the design of a mooring line to maintain the position of a floating WEC (wave energy conversion) system. The procedure to design a mooring line is set up and the safety of the designed mooring system is evaluated using commercial software, Orcaflex. The characteristics curve for one line is analyzed to determine the properties and pretension of a mooring line. While considering the ocean environmental condition and importance of a floating WEC system, a multi-line layout is determined. A 4-point mooring system with 4 lines shows the instability in the yaw motion of the floating WEC system under a designed ocean environmental condition. The redesigned 4-point mooring system with 8 lines is found to be safe on the condition of a harsh ocean environment. The floating WEC system with the redesigned mooring system also shows stable motion in surge and pitch under operating conditions. From a parametric study on the mooring line length, the extreme value of the mooring line tension is found to be very sensitive to the pretension and length of mooring line. The results of this study can contribute to the establishment of a design procedure for mooring lines.