Experimental and numerical investigation of the roll motion behavior of a floating liquefied natural gas system  

作　　者：ZHAO WenHua YANG JianMin HU ZhiQiang XIAO LongFei PENG Tao 

机构地区：[1]State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University

出　　处：《Science China Chemistry》2013年第3期629-644,共16页中国科学（化学英文版）

基　　金：supported by the Science Foundation of Science and Technology Commission of Shanghai Municipality(Grant No.11ZR1417800);the National Natural Science Foundation of China(Grant No.50879045);the LRET(Lloyds Register Educational Trust) to the joint centre involving University College London,Shanghai Jiao Tong University and Harbin Engineering University

摘　　要：The present paper does an experimental and numerical investigation of the hydrodynamic interaction and the response of a single point turret-moored Floating Liquefied Natural Gas(FLNG) system,which is a new type of floating LNG(Liquid Natural Gas) platform that consists of a ship-type FPSO hull equipped with LNG storage tanks and liquefaction plants.In particular,this study focuses on the investigation of the roll response of FLNG hull in free-decay motions,white noise waves and also in irregular waves.Model tests of the FLNG system in 60%H filling condition excited by both white noise waves and irregular waves combined with steady wind and current have been carried out.Response Amplitude Operators(RAOs) and time histories of the responses are obtained for sway,roll and yaw motions.Obvious Low Frequency(LF) components of the roll motions are observed,which may be out of expectation.To facilitate the physical understanding of this phenomenon,we filter the roll motions at the period of 30 s into two parts:the Wave Frequency(WF) motions and the Low Frequency(LF) motions respectively.The results indicate that the LF motions are closely related to the sway and yaw motions.Possible reasons for the presence of the LF motions of roll have been discussed in detail,through the comparison with the sway and yaw motions.As for the numerical part,the simulation of the modeled case is conducted with the help of the software SESAM.A good agreement between experiments and calculations is reported within the scope of trends.However,the numerical simulations should be further improved for the prediction of the FLNG system in the heading sea.The present paper does an experimental and numerical investigation of the hydrodynamic interaction and the response of a sin- gle point turret-moored Floating Liquefied Natural Gas （FLNG） system, which is a new type of floating LNG （Liquid Natural Gas） platform that consists of a ship-type FPSO hull equipped with LNG storage tanks and liquefaction plants. In particular, this study focuses on the investigation of the roll response of FLNG hull in free-decay motions, white noise waves and also in irregular waves. Model tests of the FLNG system in 60%H filling condition excited by both white noise waves and irregular waves combined with steady wind and current have been carried out. Response Amplitude Operators （RAOs） and time histo- ries of the responses are obtained for sway, roll and yaw motions. Obvious Low Frequency （LF） components of the roll mo- tions are observed, which may be out of expectation. To facilitate the physical understanding of this phenomenon, we filter the roll motions at the period of 30 s into two parts： the Wave Frequency （WF） motions and the Low Frequency （LF） motions re- spectively. The results indicate that the LF motions are closely related to the sway and yaw motions. Possible reasons for the presence of the LF motions of roll have been discussed in detail, through the comparison with the sway and yaw motions. As for the numerical part, the simulation of the modeled case is conducted with the help of the software SESAM. A good agreement between experiments and calculations is reported within the scope of trends. However, the numerical simulations should be further improved for the prediction of the FLNG system in the heading sea.

关 键 词：FLNG HYDRODYNAMICS roll motion behavior model tests coupled effects 

分 类 号：U469.11[机械工程—车辆工程] TE646[交通运输工程—载运工具运用工程]