CAJ | 학술논문

为了观察并列双立管涡激振动中尾流及升阻力的变化情况，采用CFX数值模拟和实验相结合的方法对单立管及中心间距为2～8倍直径的并列双立管进行研究，CFX计算时考虑流固耦合的作用。结果表明：在间距为3倍立管直径时升力幅值出现最大值，此时两立管拖曳力一致，升力相位差为180°，且此时尾流叠加区域产生了一个与涡泄频率一致的速度变化场，导致立管的拖曳力周期与升力周期相同；随着间距的增加，一侧立管运动轨迹从椭圆形向8字形转变，可见低倍立管间距时，立管间的相互作用明显，随着距离的增大，影响将逐渐减弱。因此立管设计安装时中心距离应远离3倍直径，最好在8倍直径附近比较安全。
위료관찰병렬쌍립관와격진동중미류급승조력적변화정황，채용CFX수치모의화실험상결합적방법대단립관급중심간거위2～8배직경적병렬쌍립관진행연구，CFX계산시고필류고우합적작용。결과표명：재간거위3배립관직경시승력폭치출현최대치，차시량립관타예력일치，승력상위차위180°，차차시미류첩가구역산생료일개여와설빈솔일치적속도변화장，도치립관적타예력주기여승력주기상동；수착간거적증가，일측립관운동궤적종타원형향8자형전변，가견저배립관간거시，립관간적상호작용명현，수착거리적증대，영향장축점감약。인차립관설계안장시중심거리응원리3배직경，최호재8배직경부근비교안전。
In order to research the wake and force in vortex-induced vibration ( VIV) , Ansys-CFX and model test are used for the VIV of single riser and the two risers in 2~8D spacing.Fluid-structure interaction is considered in the CFX.It is shown that, the lift force of the two risers comes to maximum in 3D spacing, the phase difference of drag force is 0°and lift force is 180°in this case, and a variable velocity field with a frequency the same as vortex shedding is generated in the overlapped area which leads to the period of drag force the same as that of lift force.It can be concluded that the interaction between the two par-allel risers is significant when the risers are brought to a small distance for the trajectory of riser changes from oval to curve 8 as the spacing is increased.So when installing the riser, the distance should be around 8D spacing.