海洋温差能发电冷水管涡激振动性能

Vortex-Induced Vibration Performance of OTEC Cold Water Pipe

以海洋温差能发电(Ocean Thermal Energy Conversion,OTEC)平台的冷水管为研究对象,根据结构方程和尾流振子方程建立冷水管流固耦合模型,采用有限元方法和Newmark-β法对冷水管涡激振动(Vortex-Induced Vibration,VIV)进行时域分析,并在MATLAB软件中开发相应的求解程序。针对冷水管所面临的复杂工况,分别研究外部流场、内部流场、长径比和压载质量等因素对VIV产生的影响。结果表明:随着外流流速和长径比的增大,冷水管横流向VIV模态和振动幅值也发生相应改变,振动强度呈现波动上升;在不发生动态失稳的情况下,内流流速的增加可有效减小冷水管横流向振动幅值,压载质量可大幅减小冷水管自由端的振动位移。

Taken the Ocean Thermal Energy Conversion(OTEC)cold water pipe as the research object,the fluid-structure coupling model of the cold water pipe is established through the structural equation and wake oscillator equation,the time domain analysis of the Vortex-Induced Vibration(VIV)of the cold water pipe is performed by the finite element method and Newmark-β method,and the corresponding solving program is developed in the MATLAB software.In view of the complicated working conditions faced by the cold water pipe,the effects of external flow field,internal flow field,length-diameter ratio and ballast mass on the VIV are studied respectively.The results show that:with the increase of external flow velocity and length-diameter ratio,the mode and amplitude of the transverse VIV of the cold water pipe change correspondingly,and the vibration intensity fluctuates;under the condition that dynamic instability does not occur,the increase of internal flow velocity can effectively reduce the transverse vibration amplitude,and the ballast mass can significantly reduce the vibration displacement of the free end of the cold water pipe.