Spar型浮式风力机涡激运动特性及其抑制研究

为减轻涡激运动对系泊结构的疲劳破坏,提出一种波纹柱体结构,探讨其涡激运动特性及抑制机理。结构与流体的非线性耦合作用通过用户自定义函数（UDF）和动网格技术实现,运动微分方程采用四阶龙格-库塔法求解。研究发现,波纹柱体与裸圆柱结构的涡激运动特性明显不同。裸圆柱随折合速度的增加呈明显的锁定特性,而波纹柱体结构的涡激响应特性与波纹高度Hw/D相关。当波纹高度Hw/D=0.01和0.05时亦会发生锁定现象,但锁定区间较裸圆柱小,当波纹高度Hw/D=0.02~0.04时结构不再发生锁定问题。结果表明,波纹结构对柱体的涡激运动有明显抑制作用。

STUDY ON VORTEX-INDUCED MOTION CHARACTERISTICS AND SUPPRESSION OF SPAR-TYPE FLOATING OFFSHORE WIND TURBINE

In order to mitigate the fatigue damage of the riser and mooring system by vortex-induced motion（VIM）, in the present work, a numerical simulation for the characteristics of VIM and suppression mechanism of a new wavy cylindrical structure is proposed. The nonlinear coupling interaction between the structure and fluid is performed by user-defined function （UDF） and dynamic mesh techniques,and the differential equations of motion are solved by the fourth-order Runge-Kutta methods. It was found that the VIM characteristics of the wavy cylinders and cylinder were significantly different. The cylinder shows a significant lock-in characteristic with the increasing reduced velocity,while the response characteristic of the wavy cylinders are related to the wave height Hw/D. The lock-in phenomenon also occurs when the wave height is Hw/D=0.01 and 0.05,but the lock-in region is smaller than that of circular cylinder,and the lock-in problem is no longer occurs when the wavy height is Hw/D=0.02-0.04. The results show that the wavy cylinders have a significant suppression effect on the VIM.