Hydrodynamics Study of Riser with Helical Strakes Oscillating in Flow

doi:10.16183/j.cnki.jsjtu.2020.234

Abstract

Abstract:

To reduce the vibration damage to the riser, hydrodynamic parameters of a smooth riser and a riser with triple symmetrically distributed helical strakes are evaluated in an experiment. The wave and current in natural environment are conceptualized to the experimental condition of the oscillatory flow and the uniform flow. Experiment cases are divided into the static flow and the uniform flow, while the risers oscillate along the in-line, the transverse, and the diagonal direction. The added mass coefficient C_m and the drag coefficient C_d are calculated from experimental data by using the Morison equation. The results of the riser with strakes indicate that C_m is independent of the Keulegan-Carpenter (KC) number and the oscillating direction. C_d is found to be in inverse proportion to the ratio of 1/3 power of the KC number and the maximum flow speed to oscillatory velocity. This finding is consistent with the format of Morison parameters of a flat plate in oscillatory flow, which endows the classical theory with novel validation and implication in the design of a riser. Under the same condition, the C_d of the helical strake riser is promoted over 273% than the bare riser, which indicates that the helical strakes efficiently reduce the influence of oscillation under complex conditions. The results provide a new solution for vibration reduction of offshore structures, which is of high value in ocean engineering.

Key words: hydrodynamics, helical strakes, riser, oscillation

CLC Number:

O352

LI Ang, SUN Ren. Hydrodynamics Study of Riser with Helical Strakes Oscillating in Flow[J]. Journal of Shanghai Jiao Tong University, 2021, 55(8): 907-915.

Figures/Tables 13

Fig.1

Tab.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Fig.12

References 27

[1]	WANG J S, FAN D X, LIN K. A review on flow-induced vibration of offshore circular cylinders[J]. Journal of Hydrodynamics, 2020, 32(3):415-440. doi: 10.1007/s42241-020-0032-2 URL
[2]	巫志文, 陆启贤, 梅国雄. 随机波浪和涡流联合作用下海洋立管多频参数激励振动响应[J]. 船舶力学, 2020, 24(5):599-610.
	WU Zhiwen, LU Qixian, MEI Guoxiong. Multi-frequency parametrically excited vibrations of marine riser under simultaneous random waves and vortex[J]. Journal of Ship Mechanics, 2020, 24(5):599-610.
[3]	丁继超, 何立东, 冀沛尧. 半主动调谐质量阻尼器控制管道振动实验研究[J]. 噪声与振动控制, 2019, 39(3):215-220.
	DING Jichao, HE Lidong, JI Peiyao. Experiment study on semi-active pipeline vibration control with tuning mass dampers[J]. Noise and Vibration Control, 2019, 39(3):215-220.
[4]	VANDIVER J K, SWITHENBANK S, JAISWAL V, et al. The effectiveness of helical strakes in the suppression of high-mode-number VIV[C]//Offshore Technology Conference. Houston, Texas, USA: OTC, 2006: 1-9.
[5]	SUI J, WANG J S, LIANG S P, et al. VIV suppression for a large mass-damping cylinder attached with helical strakes[J]. Journal of Fluids and Structures, 2016, 62:125-146. doi: 10.1016/j.jfluidstructs.2016.01.005 URL
[6]	沙勇, 曹静, 张恩勇, 等. 抑制涡激振动的螺旋列板设计参数研究[J]. 海洋工程, 2013, 31(1):43-48.
	SHA Yong, CAO Jing, ZHANG Enyong, et al. Helical strakes for marine risers VIV suppression and its design parameters selection[J]. The Ocean Engineering, 2013, 31(1):43-48. doi: 10.1016/S0029-8018(03)00107-0 URL
[7]	李艳潇, 张淑君. 串列双立管螺旋列板抑制涡激振动的数值模拟[J]. 舰船科学技术, 2019, 41(7):100-105.
	LI Yanxiao, ZHANG Shujun. Three dimensional numerical simulation of VIV of tandem double risers by helical strakes[J]. Ship Science and Technology, 2019, 41(7):100-105.
[8]	QUEN L K, ABU A, KATO N, et al. Investigation on the effectiveness of helical strakes in suppressing VIV of flexible riser[J]. Applied Ocean Research, 2014, 44:82-91. doi: 10.1016/j.apor.2013.11.006 URL
[9]	GAO Y, FU S X, REN T, et al. VIV response of a long flexible riser fitted with strakes in uniform and linearly sheared currents[J]. Applied Ocean Research, 2015, 52:102-114. doi: 10.1016/j.apor.2015.05.006 URL
[10]	高云, 付世晓, 宋磊建. 柔性立管涡激振动抑制装置试验研究[J]. 振动与冲击, 2014, 33(14):77-83.
	GAO Yun, FU Shixiao, SONG Leijian. Experimental investigation on the suppression device of VIV of a flexible riser[J]. Journal of Vibration and Shock, 2014, 33(14):77-83.
[11]	LAMBRAKOS K F, TRIANAFYLIOU M S, MOROS T. Hydrodynamic coefficients for risers with strakes[C]//Proceedings of ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. Oslo, Norway: Ocean, Offshore, and Arctic Engineering Division, 2009: 467-471.
[12]	FAN D, JODIN G, CONSI T R, et al. A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics[J]. Science Robotics, 2019, 4(36):5063.
[13]	XU Y W, FU S X, CHEN Y, et al. Experimental investigation on vortex induced forces of oscillating cylinder at high Reynolds number[J]. Ocean Systems Engineering, 2013, 3(3):167-180. doi: 10.12989/ose.2013.3.3.167 URL
[14]	陈蓥, 付世晓, 许玉旺, 等. 均匀流中近壁面垂直流向振荡圆柱水动力特性研究[J]. 物理学报, 2013, 62(6):329-338.
	CHEN Ying, FU Shixiao, XU Yuwang, et al. Hydrodynamic characters of a near-wall circular cylinder oscillating in cross flow direction in steady current[J]. Acta Physica Sinica, 2013, 62(6):329-338.
[15]	LIN K, FAN D X, WANG J S. Dynamic response and hydrodynamic coefficients of a cylinder oscillating in crossflow with an upstream wake interference[J]. Ocean Engineering, 2020, 209:107520. doi: 10.1016/j.oceaneng.2020.107520 URL
[16]	WU B H, LE GARREC J, FAN D X, et al. Kill line model cross flow inline coupled vortex-induced vibration[C]//Proceedings of ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. Trondheim, Norway: ASME, 2017: 61191.
[17]	LE GARREC J, FAN D X, WU B H, et al. Experimental investigation of cross flow-inline coupled Vortex-Induced Vibration on riser with finite length buoyancy module[C]//OCEANS 2016 MTS/IEEE Monterey. Piscataway, NJ, USA: IEEE, 2016: 1-7.
[18]	FAN D X, WANG Z C, TRIANTAFYLLOU M S, et al. Mapping the properties of the vortex-induced vibrations of flexible cylinders in uniform oncoming flow[J]. Journal of Fluid Mechanics, 2019, 881:815-858. doi: 10.1017/jfm.2019.738 URL
[19]	FAN D X, TRIANTAFYLLOU M S. Vortex induced vibration of riser with low span to diameter ratio buoyancy modules[C]//The 27th International Ocean and Polar Engineering Conference. San Francisco, California, USA: International Society of Offshore and Polar Engineers, 2017: 1151-1159.
[20]	KEULEGAN G H, CARPENTER L H. Forces on cylinders and plates in an oscillating fluid[J]. Journal of Research of the National Bureau of Standards, 1958, 60(5):423. doi: 10.6028/jres.060.043 URL
[21]	SARPKAYA T. Force on a circular cylinder in viscous oscillatory flow at low Keulegan-Carpenter numbers[J]. Journal of Fluid Mechanics, 1986, 165:61. doi: 10.1017/S0022112086002999 URL
[22]	FAN D X, ZHANG X T, TRIANTAFYLLOU M S. Drag coefficient enhancement of dual cylinders in oscillatory flow[C]//The 27th International Ocean and Polar Engineering Conference. San Francisco, California, USA: International Society of Offshore and Polar Engineers, 2017: 1198-1205.
[23]	WILLIAMSON C H K. Sinusoidal flow relative to circular cylinders[J]. Journal of Fluid Mechanics, 1985, 155:141-174. doi: 10.1017/S0022112085001756 URL
[24]	GOPALKRISHNAN R. Vortex-induced forces on oscillating bluff cylinders[D]. Cambridge, MA, USA: Massachusetts Institute of Technology, 1993.
[25]	ARONSEN K H. An experimental investigation of in-line and combined in-line and cross-flow vortex induced vibrations[D]. Trondheim, Norway: Norwegian University of Science and Technology, 2007.
[26]	GRAHAM J M R. The forces on sharp-edged cylinders in oscillatory flow at low Keulegan-Carpenter numbers[J]. Journal of Fluid Mechanics, 1980, 97(2):331-346. doi: 10.1017/S0022112080002595 URL
[27]	FALTINSEN O M. Sea loads on ships and offshore structures[M]. Cambridge: Cambridge University Press, 1990: 238-240.

KC	v_∞/v₀
KC	工况1	工况2	工况3	工况4	工况5	工况6	工况7	工况8	工况9
0.5	0.00	N/A	N/A	N/A	1.00	1.25	1.50	3.00	5.00
1	0.00	N/A	0.50	0.75	1.00	1.25	1.50	3.00	5.00
2	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00
3	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00
4	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00
5	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00
7	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00
10	0.00	0.25	0.50	0.75	1.00	1.25	1.50	3.00	5.00