目前常见的提升圆筒型浮式生产储装置(Floating production storage and offloading vessels,FPSO)垂荡性能的方法是通过增加刚度使垂荡固有周期增大到20 s以上,远离常见波浪周期,但这使得垂荡固有周期与纵摇固有周期的比值接近1∶2,可...目前常见的提升圆筒型浮式生产储装置(Floating production storage and offloading vessels,FPSO)垂荡性能的方法是通过增加刚度使垂荡固有周期增大到20 s以上,远离常见波浪周期,但这使得垂荡固有周期与纵摇固有周期的比值接近1∶2,可能会导致参数激励现象的发生。因此本文针对此类圆筒型FPSO系统的参数激励非线性运动展开研究。考虑规则波建立了系统单自由度参数激励纵摇方程,本文中采用多尺度法求解运动方程的一次近似解析解,基于Lyapunov定理分析解的稳定性,以分析规则参数激励下圆筒型FPSO纵摇失稳的机理。最后,结合多尺度法与数值方法进行参数敏感性分析。结果表明,使参数激励周期与纵摇固有周期的比值远离1/2、降低参数激励幅值和增大纵摇阻尼的3种方式均能够有效避免大幅参数激励的发生。展开更多
The purpose of this study is to investigate the suppression effect of a nonlinear energy sink(NES)on the wind-vortex-induced pipe vibration and explore the influence of damping,stiffness,and NES installation position ...The purpose of this study is to investigate the suppression effect of a nonlinear energy sink(NES)on the wind-vortex-induced pipe vibration and explore the influence of damping,stiffness,and NES installation position on the suppression effect.In this work,the wind-vortex-induced vibration of an elastic pipe of a deepwater jacket was studied,and vibrations were suppressed by using an NES.A van der Pol wake oscillator was used to simulate vortex-induced force,and the dynamic equation of the pipe considering the NES was established.The Galerkin method was applied to discretize the motion equation,and the vortex-induced vibration(VIV)of the pipe at reduced wind speeds was numerically analyzed.The novelty of this research is that particle swarm optimization was used to optimize the parameters of the NES to improve vibration suppression.The influence of the installation position,nonlinear stiffness,and damping parameters of the NES on vibration suppression was analyzed.Results showed that the optimized parameter combinations of the NES can effectively reduce wind-vortex-induced pipe vibration.The installation position of the NES had a significant effect on vibration suppression,and the midpoint of the pipe was the optimal NES installation position.An increase in stiffness or a 10% decrease in damping may cause vibration suppression failure.The results of this study provide some guidance for VIV suppression in deepwater jacket pipes.展开更多
文摘目前常见的提升圆筒型浮式生产储装置(Floating production storage and offloading vessels,FPSO)垂荡性能的方法是通过增加刚度使垂荡固有周期增大到20 s以上,远离常见波浪周期,但这使得垂荡固有周期与纵摇固有周期的比值接近1∶2,可能会导致参数激励现象的发生。因此本文针对此类圆筒型FPSO系统的参数激励非线性运动展开研究。考虑规则波建立了系统单自由度参数激励纵摇方程,本文中采用多尺度法求解运动方程的一次近似解析解,基于Lyapunov定理分析解的稳定性,以分析规则参数激励下圆筒型FPSO纵摇失稳的机理。最后,结合多尺度法与数值方法进行参数敏感性分析。结果表明,使参数激励周期与纵摇固有周期的比值远离1/2、降低参数激励幅值和增大纵摇阻尼的3种方式均能够有效避免大幅参数激励的发生。
基金supported by the Tianjin Municipal Transportation Commission Project(No.2018-b2).
文摘The purpose of this study is to investigate the suppression effect of a nonlinear energy sink(NES)on the wind-vortex-induced pipe vibration and explore the influence of damping,stiffness,and NES installation position on the suppression effect.In this work,the wind-vortex-induced vibration of an elastic pipe of a deepwater jacket was studied,and vibrations were suppressed by using an NES.A van der Pol wake oscillator was used to simulate vortex-induced force,and the dynamic equation of the pipe considering the NES was established.The Galerkin method was applied to discretize the motion equation,and the vortex-induced vibration(VIV)of the pipe at reduced wind speeds was numerically analyzed.The novelty of this research is that particle swarm optimization was used to optimize the parameters of the NES to improve vibration suppression.The influence of the installation position,nonlinear stiffness,and damping parameters of the NES on vibration suppression was analyzed.Results showed that the optimized parameter combinations of the NES can effectively reduce wind-vortex-induced pipe vibration.The installation position of the NES had a significant effect on vibration suppression,and the midpoint of the pipe was the optimal NES installation position.An increase in stiffness or a 10% decrease in damping may cause vibration suppression failure.The results of this study provide some guidance for VIV suppression in deepwater jacket pipes.