Experimental study on mooring tension of a moored rectangular cylinder under freak wave

Pan Wenbo; Cui Cheng; He Meng; Zeng Fanxu; Liang Chen; Zhang Ningchuan

doi:10.3969/j.issn.0253-4193.2020.09.010

Volume 42 Issue 9

Nov. 2020

Turn off MathJax

Article Contents

Article Navigation > Haiyang Xuebao > 2020 > 42(9): 87-99

Pan Wenbo，Cui Cheng，He Meng, et al. Experimental study on mooring tension of a moored rectangular cylinder under freak wave[J]. Haiyang Xuebao，2020, 42(9)：87–99 doi: 10.3969/j.issn.0253-4193.2020.09.010

Citation:

PDF( 4903 KB)

Experimental study on mooring tension of a moored rectangular cylinder under freak wave

doi: 10.3969/j.issn.0253-4193.2020.09.010

1.
State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China
2.
Tianjin Research Institute for Water Transport Engineering, M.O.T., Tianjin 300456, China

Received Date: 2019-07-06
Rev Recd Date: 2019-11-19

Available Online: 2021-04-21

Publish Date: 2020-09-25

Abstract

Abstract

Based on extensive experiments on the mooring tension of a rectangular cylinder, the present investigation compares the mooring tension of a floating rectangular cylinder under freak and random waves and quantifies the difference through experimental measurements. The effects of the relative wave height, relative period and freak wave parameter α₁ on the mooring tension are investigated. The results show that, the freak wave parameter α₁ has significant effect on the mooring tension of the floater. With α₁=2.0～2.83, the maximum mooring tension under freak wave were 1.9 times larger than that under random wave. With H_s/d=0.032～0.097, the maximum mooring tension under freak wave are significantly larger than those under irregular waves, but the 1/3 large value and average value under freak and irregular waves are almost the same. For the effect of the relative period, the critical variation of mooring tension occur at period within T_p<T_0p. The time-frequency spectra of the mooring tension under freak and random waves are calculated by wavelet analysis to investigate the time-frequency structure characteristics and variation. The time-frequency characteristics of mooring tension are significantly different from those of random wave.
- freak wave,
- moored rectangular cylinder,
- mooring tension,
- wavelet analysis

FullText(HTML)

References(19)

References

[1]	Slunyaev A, Kharif C, Pelinovsky E, et al. Nonlinear wave focusing on water of finite depth[J]. Physica D: Nonlinear Phenomena, 2002, 173(1/2): 77−96.
[2]	Clauss G F, Schmittner C E, Henning J. Systematically varied rogue wave sequences for the experimental investigation of extreme structure behavior[J]. Journal of Offshore Mechanics and Arctic Engineering, 2006, 130(2): 1030−1036.
[3]	Pei Yuguo, Zhang Ningchuan, Zhang Yunqiu. Efficient Generation of Freak Waves in Laboratory[J]. China Ocean Engineering, 2007, 21(3): 515−523.
[4]	Cui Cheng, Zhang Ningchuan, Yu Yuxiu, et al. Numerical study on the effects of uneven bottom topography on freak waves[J]. Ocean Engineering, 2012, 54: 132−141. doi: 10.1016/j.oceaneng.2012.06.021
[5]	El Moctar O, Schellin T E, Jahnke T, et al. Wave load and structural analysis for a jack-up platform in freak waves[J]. Journal of Offshore Mechanics and Arctic Engineering, 2007, 131(2): 623−632.
[6]	Rudman M, Cleary P W. Rogue wave impact on a tension leg platform: the effect of wave incidence angle and mooring line tension[J]. Ocean Engineering, 2013, 61: 123−138. doi: 10.1016/j.oceaneng.2013.01.006
[7]	Zhao Xizeng, Ye Zhouteng, Fu Yingnan, et al. A CIP-based numerical simulation of freak wave impact on a floating body[J]. Ocean Engineering, 2014, 87: 50−63. doi: 10.1016/j.oceaneng.2014.05.009
[8]	Ning Dezhi, Wang Rongquan, Chen Lifen, et al. Extreme wave run-up and pressure on a vertical seawall[J]. Applied Ocean Research, 2017, 67: 188−200. doi: 10.1016/j.apor.2017.07.015
[9]	Clauss G F, Schmittner C E, Stutz K. Freak wave impact on semisubmersibles-time-domain analysis of motions and forces[C]// Proceedings 13th International Offshore and Polar Engineering Conference, Honolulu, USA, 2003. Honolulu, USA: International Society of Offshore and Polar Engineers, 2003.
[10]	Schmittner C E. Rogue wave impact on marine structures[D]. Berlin: Technische Universität Berlin, 2005.
[11]	沈玉稿, 杨建民, 李欣. 极限波浪作用下半潜平台运动响应时域数值模拟[J]. 海洋工程, 2013, 31(3): 9−17. Shen Yugao, Yang Jianmin, Li Xin. Numerical investigation on the motion response of semisubmersible platform under extreme waves[J]. The Ocean Engineering, 2013, 31(3): 9−17.
[12]	Deng Yanfei, Yang Jianmin, Xiao Longfei, et al. An experimental investigation on the motion and dynamic responses of a semisubmersible in freak waves[C]//Proceedings of the 17th National Conference on Ocean Engineering. Beijing: China Ocean Press, 2015: 182−189.
[13]	Gao Ningbo, Yang Jianmin, Zhao Wenhua, et al. Numerical simulation of deterministic freak wave sequences and wave-structure interaction[J]. Ships and Offshore Structures, 2016, 11(8): 802−817. doi: 10.1080/17445302.2015.1073864
[14]	Pan Wenbo, Zhang Ningchuan, Huang Guoxing, et al. Experimental study on motion responses of a moored rectangular cylinder under freak waves (I: Time-domain study)[J]. Ocean Engineering, 2018, 153: 268−281. doi: 10.1016/j.oceaneng.2018.01.084
[15]	Chien H, Kao C, Chuang L Z H. On the characteristics of observed coastal freak waves[J]. Coastal Engineering Journal, 2002, 44(4): 301−319. doi: 10.1142/S0578563402000561
[16]	Journee J M. Motions of rectangular barges[C]//Proceedings 10th International Conference on Offshore Mechanics and Arctic Engineering. Stavanger, Norway: American Society of Mechanical Engineer, 1991: 641.
[17]	Osborne A R, Onorato M, Serio M. The nonlinear dynamics of rogue waves and holes in deep-water gravity wave trains[J]. Physics Letters A, 2000, 275(5/6): 386−393.
[18]	Song Yue, Zhang Ningchuan, Huang Guoxing, et al. Experimental study on motions of tunnel element during immersion standby stage in long wave regime[J]. Ocean Engineering, 2018, 161: 29−46. doi: 10.1016/j.oceaneng.2018.04.089
[19]	Pinkster J A. Mean and low frequency wave drifting forces on floating structures[J]. Ocean Engineering, 1979, 6: 593−615. doi: 10.1016/0029-8018(79)90010-6