摘要：Slender flexible cylindrical structures, such as marine risers and the tendons of tension leg platforms, have been widely used in offshore engineering. This paper mainly investigates the hydrodynamic characteristics of two flexible cylinders with unequal diameters in a side-by-side arrangement subjected to flow-induced vibration (FIV). A series of model tests are carried out in a towing tank. The aspect ratios and mass ratios of the two flexible cylinders are 350/181 and 1.90/1.47, respectively. A diameter ratio of 0.5 and a centre-to-centre spacing ratio of 6.0 are selected for the experimental tests. The experimental results of two cases, namely, those of an unequal-diameter cylinder system and an equal-diameter cylinder system, are compared and discussed. With the comparison of the hydrodynamic coefficients of large cylinder #1 and small cylinder #2 in the unequal-diameter cylinder system and small cylinder #3 in the equal-diameter cylinder system, the FIV features of two side-by-side unequal-diameter cylinders are systematically explored. The in-line (IL) and cross-flow (CF) vibration responses and hydrodynamic characteristics are specifically investigated. The wake effect caused by the vibration of the cylinders is more obvious and important for small cylinder #2 in the unequal-cylinder system. The lift coefficient C-Ly and fluctuating force coefficient C-CF_rms of small cylinder #2 in the CF direction are obviously higher than those of the isolated cylinder in the larger reduced velocity range (V-rs = 7.52-17.54). The added mass coefficient Ca-x, varying drag coefficient C-Dx and fluctuating force coefficient C-IL_rms in the IL direction decrease significantly when reduced velocity V-rs increases from 22.54 to 25.05. Compared with the two side-by-side cylinders in the equal-diameter cylinder system, the two cylinders in the unequal-diameter cylinder system exhibit a stronger interaction under the initial spacing ratio (S/d = 6.0).

关键字：Side-by-side; Flow-induced vibration (FIV); Unequal-diameter; Hydrodynamic characteristics; Flexible cylinder

ISSN号：0029-8018

卷、期、页：卷: 243

发表日期：2022-01-01

影响因子：3.794800

期刊分区（SCI为中科院分区）：三区

收录情况：SCI（科学引文索引印刷版）,地学领域高质量科技期刊分级目录（国外T1）,SCIE（科学引文索引网络版）

发表期刊名称：OCEAN ENGINEERING

参与作者：徐万海,张倩楠,马烨璇,何超,赖姜

第一作者：王莹莹

论文类型：期刊论文

论文概要：徐万海,张倩楠,马烨璇,王莹莹,何超,赖姜，Hydrodynamic characteristics of two side-by-side flexible cylinders with different diameters experiencing flow-induced vibration，OCEAN ENGINEERING，2022，卷: 243

论文题目：Hydrodynamic characteristics of two side-by-side flexible cylinders with different diameters experiencing flow-induced vibration