中文摘要：

对于立管涡激振动动力响应问题,人们通常采用线性化处理方法,忽略了立管的非线性效应。如常用的立管分析软件Oraflex,在计算涡激振动时不考虑立管与流体的流固耦合作用。在低模态、小变形振动时,线性化处理是可以接受的,但是在大长径比、多模态振动、高雷诺数情况下,立管在高阶振动时产生较大变形,此时必须考虑立管的流固耦合作用。基于CFX软件对考虑流固耦合的柔性立管涡激振动进行了研究,分析了立管振动对流场的扰动,重点研究了质量比为7时,不同约化速度下立管的两向振动幅值、升阻力系数等问题。研究表明,在非锁定区,立管的顺流向振幅接近甚至大于横向振幅,在流速较小时应重视顺流向振动的影响;在锁定区,横向振幅远大于顺流向振幅,横向振动的无量纲振幅达到0.8左右。

英文摘要：

With regard to dynamic response of（VIV）, linear elastic rod model is usually adopted and nonlinear effects are ignored, which is done in commonly used software Orcaflex. In large length-diameter ratio and multi-mode shedding and high Reynolds number conditions, nonlinear effects must be taken into consideration. VIV of flexible risers with consideration of fluid-structure interaction is analyzed in this paper based on CFX. Disturbance of flow field due to vibration was analyzed, and amplitudes and lift/drag coefficients for in-line and cross-flow vortex-induced vibration（VIV） are studied at different reduced velocities, where the mass ratio is 7.It is shown that the amplitudes of in-line VIV is close to or even larger than that of cross-flow VIV beyond the lock-in district. Amplitude for cross-flow is larger within the lock-in district and the dimensionless amplitude can reach to 0.8.