涡激诱导并列双圆柱碰撞数值模拟研究  

NUMERICAL SIMULATION ON THE VORTEX-INDUCED COLLISION OF TWO SIDE-BY-SIDE CYLINDERS

作　　者：杨明 刘巨保[1] 岳欠杯[1] 丁宇奇[1] 王明[1] Yang Ming;Liu Jubao;Yue Qianbei;Ding Yuqi;Wang Ming(College of Mechanical Science and Engineering,Northeast Petroleum University,Daqing 163318,Heilongjiang,China)

机构地区：[1]东北石油大学机械科学与工程学院

出　　处：《力学学报》2019年第6期1785-1796,共12页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(11972114,51904075,51604080);黑龙江省博士后资金(LBH-Z17037);中国博士后科学基金(2017M621240,2019M661248);黑龙江省国家自然科学青年基金培育基金(2017PYQZL-09);黑龙江省高校青年创新人才培养计划(UPYSCT-2018045,2017036);东北石油大学研究生教育创新工程(JYCX CX04 2018)资助项目

摘　　要：圆柱类结构物的涡激振动是工程中较为常见的一种现象,如果圆柱结构物之间的距离较小,就会产生涡激诱导碰撞现象,而涡激碰撞会比涡激振动对结构物疲劳破坏产生更严重的威胁.采用浸入边界法模拟流体中的动边界问题,避免了传统贴体网格方法在求解流体中存在固体间碰撞问题时出现数值求解不稳定问题,采用有限元方法对圆柱的运动和碰撞进行求解,通过数据回归方法建立了流体流动条件下的润滑模型,对不同间隙比下涡激诱导并列双圆柱振动及碰撞过程进行了数值模拟,数值结果表明,如果两圆柱产生了碰撞将会有连续的碰撞发生,碰撞时出现了多阶频率,振动主频率要比无碰撞时大,两圆柱碰撞时的相对速度比自由来流速度小;当两圆柱相互接近时,随着涡环分离角度的逐渐倾斜,横向流体力先逐渐减小,当两圆柱间涡环开始相互影响发生挤压时,横向流体力开始逐渐增大;当两圆柱开始反弹时,两圆柱间形成了低压区,改变了横向流体阻力的方向,使两圆柱又产生了接近运动,如此反复从而产生了碰撞后横向流体力和圆柱速度的振荡现象.Vortex-induced vibration of cylindrical structures is a common phenomenon in engineering.If the distance between cylindrical structures is small,vortex-induced collision will occur.Vortex-induced collision is more serious than vortex-induced vibration on the fatigue damage of the structures.The immersed boundary method was used to simulate the dynamic boundary problem in the fluid which avoided the numerical instability problem when the traditional boundaryfitting method was used to solve the collision problem between solids.The finite element method was used to simulate the motion and collision of the cylinders.The lubrication model under fluid flow condition was established by data regression method.The vortex-induced vibration and collision of two side-by-side cylinders at different initial gap ratios were simulated numerically.The numerical results show that if the collision occurs,there will be a continuous collision.Multiple frequencies occur in collisions and the main frequency of vibration is higher than that without collision.When the two cylinders collide,the relative velocity is smaller than that of free flow.When two cylinders are close to each other,the transverse fluid force decreases with the gradual inclination of vortex ring separation angle.When the vortex rings between two cylinders start to influence each other and squeeze,the transverse fluid force starts to increase gradually.When the two cylinders start to rebound,a low pressure area is formed between the two cylinders,which changes the direction of the transverse fluid force and makes the two cylinders move close to each other again.This repetition results in the oscillation of transverse fluid force and cylinder velocity after collision.

关 键 词：涡激振动 碰撞 浸入边界法 有限元法 润滑模型 

分 类 号：O352[理学—流体力学] O347.1[理学—力学]