深水SPAR风机系统全耦合动力响应分析研究

Study on full coupling dynamic responses of a deepwater SPAR wind turbine system

文章采用联合开发的计算程序对深水SPAR风机的浮体、锚泊和风机各子系统进行了水—气动力的全耦合数值分析,研究了深水浮式风机系统的动力响应特点。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NREL的5MW SPAR风机系统在随机海况下的水动力响应分析,验证了该方法的有效性,并分析了浮式风机子系统间的混合动力作用。

The method to perform coupling analysis for offshore floating wind turbines （OFWT） is developted through integrating hydrodynamic and aerodynamic modules in time domain. Morison method is used for hy-drodynamic computation of floating body and its mooring system, in which relative velocity between structure elements and waves is implemented by the Hybrid Wave Model with second order accuracy. Slender rods theories are applied on the mooring systems, and the aerodynamics load induced by wind turbine is simulat-ed by NREL＇s code-FAST. Loads and displacements are transferred between the submodules based main-ly on floating body control equations in every time step by Newmark-βmethod. Motion response of a 5MW 3 blades spar type OFWT is predicted with and without FAST to validate the combined program. A compar-ison with results from available 3D linear potential flow method in a random sea condition shows that the code is capable of hydro-aero dynamic analysis for OFWT.