CAJ | 학술논문

处于波浪和洋流中的立管两侧不断产生周期性的漩涡脱落，其诱发的涡激振动已经成为引起结构疲劳损伤的主要因素。在海洋立管尾迹区加装分隔板之后，通过阻碍上下剪切层动量交换，从而可有效抑制立管涡激振动现象。文章采用大涡模拟（LES）方法，对亚临界雷诺数流动状态Re=3900下的光滑立管以及加装分隔板长度分别为0.5~3.0倍立管直径的立管进行三维数值模拟，研究各种工况下近尾流场结构、立管升、阻力系数和泄涡发放频率的变化特征，观测其尾涡发放特点。结果表明：加装分隔板可有效抑制涡激振动，阻力系数及对应流向振动幅度均有下降。当分隔板长度为1.5倍立管直径时，漩涡发放频率大大减小，尾涡脱落位置延后，作用在结构上的平均阻力系数减小20%，达到了抑制立管涡激振动的最优效果。
처우파랑화양류중적립관량측불단산생주기성적선와탈락，기유발적와격진동이경성위인기결구피로손상적주요인소。재해양립관미적구가장분격판지후，통과조애상하전절층동량교환，종이가유효억제립관와격진동현상。문장채용대와모의（LES）방법，대아림계뢰낙수류동상태Re=3900하적광활립관이급가장분격판장도분별위0.5~3.0배립관직경적립관진행삼유수치모의，연구각충공황하근미류장결구、립관승、조력계수화설와발방빈솔적변화특정，관측기미와발방특점。결과표명：가장분격판가유효억제와격진동，조력계수급대응류향진동폭도균유하강。당분격판장도위1.5배립관직경시，선와발방빈솔대대감소，미와탈락위치연후，작용재결구상적평균조력계수감소20%，체도료억제립관와격진동적최우효과。
Risers in waves and currents on either side suffer from a constant periodic vortex shedding, induc-ing vortex-induced vibration which has become a major factor that cause the structural fatigue damage. How-ever, adding a splitter plate along the wake centerline downstream of the bluff bodies is an effective passive means of controlling fully developed vortex shedding. This phenomenon is caused by interfering with the up-per and lower shear layer momentum exchange. In this paper, work contributes for a precise Reynolds num-ber that leads to a subcritical flow regime at Reynolds number Re=3 900. Here, the unsteady flow is in-vestigated numerically with large eddy simulation. Simulations are done respectively for bare riser and those attached to splitter plate in six different gaps (L/D=0.5~3.0D). Results indicate that by adding splitter plates, vortex shedding formed in the wake is suppressed and the oscillating amplitude of the drag coeffi-cient decreases. Especially, when the plate length is 1.5 times of riser diameter, vortex shedding frequency significantly decreases. Vortex core moves towards the leading edge of the plate. Moreover, the mean drag coefficient is reduced by 20%, reaching a optimal effect in inhibition of vortex-induced vibration of riser.