浮式风机系统水-气动力耦合分析方法

将浮式风机系统中浮体的水动力分析模块与风力发电机的空气动力分析模块整合,提出了适用于深水浮式风机系统的全耦合动力响应分析方法.浮体水动力计算采用基于二阶精度的混合波浪模型(Hybrid Wave Model)的MORISON公式,锚泊系统采用细长杆理论通过非线性有限元方法实现,风机系统的空气动力分析采用基于多体气动弹性理论的FAST模块.以浮体控制方程为主体,通过模块间的载荷与位移传递在每个时间步上迭代求解,形成完全耦合的时域分析方法.通过对某SPAR风机系统在随机海况下进行了系统水动力响应分析,并与现有的三维势流理论的结果进行了比较,验证了数值分析方法的有效性.最后,对系统的动力响应进行了水-气动力的全耦合数值分析.结果表明,该方法能有效地分析浮式风机各子系统间的混合动力作用,可用于海洋风电系统开发.

Coupling Hydrodynamic and Aerodynamic Computations of Offshore Floating Wind Turbines

The method to perform coupling analysis of offshore floating wind turbines (OFWT) was developted by integrating hydrodynamic and aerodynamic modules in time domain. The Morison method was used for hydrodynamic computation of floating body and its mooring system, in which the relative velocity between structure elements and waves was implemented by the hybrid wave model with second order accuracy. Slender rods theories were applied to the mooring systems, and the wind turbine was modeled by the aero-elastic code-FAST. Loads and displacements were transferred between the submodules based mainly on floating body control equations in every time step by the Newmark- β method. Motion responses of a 5 MW 3 blades spar type OFWT was predicted with and without FAST to validate the combined program. A comparison of results from the available 3D linear potential flow method in a random sea condition shows that the code is capable of hydro-aero dynamic analysis of OFWT.