Tests for VIM of a semi-submersible platform considering yaw motion

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Journal of Vibration and Shock ›› 2019, Vol. 38 ›› Issue (19) : 168-173.

WEI Dongze1,Bai Xinglan1,Chang Shuang2

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Abstract

Here, in order to study vortex-induced motion (VIM) features of a semi-submersible platform, its flume model tests were conducted. The motion response amplitudes and frequencies of its sway, surge and yaw motions were measured under different incoming flow velocities and flow angles of 0 °, 15 °, 30 ° and 45 ° to explore key characteristics of its VIM. The results showed that there is no obvious frequency locking phenomenon in different incoming flow directions; the platform’s 3-DOF response almost linearly increases with increase in reduced velocity when the flow angle is 0 ° and 15 °; the platform’s response has resonance phenomenon when the flow angle is 30 ° and 45 ° and the reduced velocity (Ur) is close to 4~10, and the response significantly decreases after the resonance phenomenon is over, then it sharply increases again with increase in reduced speed; except under few working conditions, the platform’s sway and yaw motions are highly coupled and their response frequencies’ main peaks remain the relation of 1∶1; the natural period of yaw has almost no effect on the platform’s 3-DOF motion frequency and amplitude; when the flow angle is 45°, the platform’s yawing motion is the most strenuous, its response amplitude is several times of those for other flow angles at any reduced speed; in addition, galloping phenomenon is observed when the flow angle is 0°; self-excitation phenomenon is observed when the flow angle is 15 ° at multiple reduced speeds.

Key words

semi-submersible platform / vortex-excited motion / yaw / frequency / response amplitude.

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WEI Dongze1,Bai Xinglan1,Chang Shuang2. Tests for VIM of a semi-submersible platform considering yaw motion[J]. Journal of Vibration and Shock, 2019, 38(19): 168-173

References

[1] F.J.Huera-Huarte,Towing tank experiments on the vortex-induced vibrations of low mass ratio long flexible cylinders[J],Journal of Fluid and Structures,2014, 28:1-12.
[2] 陈正寿等,质量比对刚性圆柱体涡激振动影响的研究[J],振动与冲击,2017,3（11）:248-254.
[2] Chen Zhengshou, et al. Effect Of Mass Ratio On Vortex- induced Vibration Of A Rigid Cylinder[J].Journal Of Vibration And Shock,2017, 3(11):248-254.
[3] Fujarra A L C, Pesce C P, Flemming F, et al. Vortex-induced vibration of a flexible cantilever [J]. Journal of Fluids and Structures, 2001, 15(3): 651-658.
[4] Chen W M. Prediction Of Vortex-Induced Vibration Of Flexible Riser Using An Improved Wake-Oscillator Model[C]// ASME 2009, International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2009:377-383.
[5] W. Yao, Rajeev K. Jaiman. A harmonic balance technique for the reduced-order computation of vortex-induced vibration[J]. Journal of Fluids and Structures, 2016, 65:313-332.
[6] Yanguo Sun, Mingshui Li, Haili Liao. Nonlinear approach of vortex-induced vibration for line-like structures[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2014, 124:1-6.
[7] J.V. Ulveseter, S. Sævik, C.M. Larsen. Time domain model for calculation of pure in-line vortex-induced vibrations[J]. Journal of Fluids and Structures, 2017, 68:158-173.
[8] Yu Duanmu, LuZoua, DechengWan, Numerical analysis of multi-modal vibrations of a vertical riser in step currents[J], Ocean Engineering, 2018, 152: 428-442.
[9] Jauvtis N, Williamson C H K. Vortex-induced vibration of a cylinder with two degrees of freedom [J]. Journal of Fluids and Structures, 2003, 17(7): 1035-1042.
[10] Williamson C H K, Jauvtis N. A high-amplitude 2T mode of vortex-induced vibration for a light body in XY motion [J]. European Journal of Mechanics-B/Fluids, 2004, 23(1): 107-114.
[11] Jauvtis N, Williamson C H K. The effect of two degrees of freedom on vortex-induced vibration at low mass and damping [J]. Journal of Fluid Mechanics, 2004, 509: 23-62.
[12] Govardhan R N, Williamson C H K. Defining the ‘modified Griffin plot in vortex-induced vibration: revealing the effect of Reynolds number using controlled damping [J]. Journal of Fluid Mechanics, 2006, 561: 147-180.
[13] Morse T L, Williamson C H K. The effect of Reynolds number on the critical mass phenomenon in vortex-induced vibration [J]. Physics of Fluids (1994-present), 2009, 21(4): 45-105.
[14] Kokkinis T, Sandstrom R E, Jones H T, et al. Development of a Stepped Line Tensioning Solution for Mitigating VIM Effects in Loop Eddy Currents for the Genesis Spar[C]//ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. American Society of Mechanical Engineers, 2004: 995-1004.
[15] Zhengdong Cui,Bin Teng.Two-dimensional numerical study of vortex-induced vibration and galloping of square ant. d rectangular cylinders in steady flow[J].Ocean Engineering,2015（106）；189-206.
[16] Agbomerie Charles Odijie,Effect of Vortex Induced Vibration on a Paired-Column Semi-submersible Platform[J],International Journal of Structural Stability and Dynamics. 2015,15(8): 1540019 (1-22).
[17] Seung Jun Kim,Numerical simulation of vortex-induced motions of a deep-draft paired-column semi-submersible offshore platform[J]. Ocean Engineering,2018,149(1):291-304.
[18] Goncalves R T, Rosetti G F, Fujarra A L C, et al. Experimental study on vortex-induced motions of a semi-submersible platform with four square columns, Part I: Effects of current incidence angle and hull appendages [J]. Ocean Engineering, 2012, 54: 150-169.
[19] Goncalves R T, Rosetti G F, Fujarra A L C, et al. Experimental study on vortex-induced motions of a semi-submersible platform with four square columns, Part II: Effects of surface waves, external damping and draft condition[J]. Ocean Engineering, 2013, 62: 10-24.
[20] Goncalves R T. Experimental study of column shape and the roughness effect on the vortex-induced motions of deep-draft semi-submersible platform[J]. Ocean Engineering, 2018, 149(1): 127-141.
[21] Blevins R D, Flow induced vibration [M]. New York: Van Nostrand Reinhond, 1990.
[22] 邓见等, 方柱绕流横向驰振及涡激振动数值模拟[J].浙江大学学报（工业版），2005, 39(4):595-599.
[22] Deng Jian, et al. Numerical Study Of Transverse Galloping And Vortex-induced Of Square Cylinder[J]. Journal Of Zhejiang University(Engineering Science), 2005, 39(4):595-599.
[23] 李磊, 考虑尾流影响的张力腿平台涡激运动分析方法研究[D].中国海洋大学，2015.
[23] Li Lei, Research on The Analysis Method of Vortex Induced Motion of Tension Leg Platform Considering the Impact of Wake[D]. Ocean University Of China, 2015.