一种改进的离散涡方法及其在涡激运动中的应用  

An improved discrete vortex method and its application on the vortex induced motion

作　　者：孙雷[1] 丁云峰 郑锦涛 宗智[1] SUN Lei;DING Yun-feng;ZHEN Jin-tao;ZONG Zhi(School of Naval Architecture,Dalian University of Technology,Dalian 116024,China;Wuhan No.2 Ship Design Institute,Wuhan 430064,China)

机构地区：[1]大连理工大学船舶工程学院,辽宁大连116024 [2]武汉第二船舶设计研究所,武汉430064

出　　处：《船舶力学》2020年第7期839-851,共13页Journal of Ship Mechanics

基　　金：国家自然科学基金面上项目(51679035);国家自然科学基金青年科学基金项目(51309051);教育部博士点基金新教师课题(20130041120008);中央高校基本科研业务费专项资金资助(DUT2017TB05);辽宁省“兴辽英才计划”资助项目(XLYC1908027)。

摘　　要：海洋平台的涡激运动(VIM)会使与之连接的锚链和立管系统发生严重的疲劳破坏,缩短其疲劳寿命,是海洋工程领域的研究热点。离散涡模型(DVM)具有不受网格限制、在涡量集中区分辨率高、可用大时间步长模拟高雷诺数流场的特点。本文应用满足流函数方程的离散涡模型模拟了高雷诺数下二维圆柱绕流和涡激振动(VIV)问题,有效还原了涡激振动中的锁定现象,验证了模型的准确性。同时提出该模型对多体结构涡激运动求解的处理方式。利用该方法模拟了二维单柱Spar平台以及多柱半潜平台模型的涡激运动,通过对平台受力曲线、横荡与纵荡位移以及频率响应的分析,得出了平台涡激运动的普遍规律,为Spar和半潜平台的结构设计提供了参考。Offshore platforms are exposed to currents in deep-sea state and suffer from the danger of Vortex-Induced Motion(VIM),which may lead to the fatigue damage of the anchor chains and risers attached and reduction of their fatigue life.The study on the vortex induced motion has been a hot spot for ocean engineering.The discrete vortex method(DVM)is a well-used computational fluid dynamic tool to simulate the flow field at high Reynold numbers for its mesh-free characteristic,high resolution and larger time-step.An improved DVM based on the vorticity and stream function formulation is applied to simulate typical problems of flow around a two-dimensional fix cylinder and VIV of an elastically-mounted cylinder.The lock-in effect is well reproduced to verify the accuracy of this model.According to the special treatment proposed to deal with vortex-induced motion of multibody structures,the VIMs of two-dimensional single-column Spar and multicolumn semi-submerged platforms are then simulated.By analyzing the loads,structural and frequency responses of the platforms,the mechanism on VIM is partly revealed.Some principles are concluded,which provide reference for the structural design of Spar and semi-submerged platforms.

关 键 词：离散涡方法 多体结构 海洋平台 涡激运动 

分 类 号：U661.1[交通运输工程—船舶及航道工程]