垂荡板对浮式风力机Spar平台的动态响应的影响

Influence of heave plate on hydrodynamic characteristics of floating wind turbine Spar platform

为探究垂荡板对漂浮式风力机Spar平台动态响应的影响,利用风压模型模拟风力机风轮的气动载荷,基于势流理论的三维辐射/绕射方法计算波浪载荷,忽略海流沿水深的速度变化且认为海上结构的作用力只由拖曳力组成,建立基于OC3-Hywind Spar Buoy平台的NREL 5 MW浮式风力机整机模型,应用数值计算方法对附有不同数目和不同厚度垂荡板的漂浮式风力机Spar平台进行动态响应分析,得出结构运动的幅频特性。结果表明:随着垂荡板数目的增多,Spar平台的动态响应就越小,附加质量就越大,但其动态响应并未按着线性关系减小,虽有降低平台动态的效果但不明显;随着板厚的增加,整体结构的附加质量也随之增大,纵荡RAO和纵摇RAO减小;垂荡运动响应随着板厚度的增加而减弱,然而在板厚度增加到0.4 m时,整体结构的纵荡和纵摇响应反而会增加。

In order to investigate the dynamic response of heave plates on Spar wind turbine platform under forced vibra- tion, using the wind pressure model simulation of the wind turbine rotor aerodynamic load, based on the potential flow theory of three-dimensional radiation/diffraction method to calculate wave load, ignoring current along the depth of speed change and thinking that only the power of the offshore structure was composed of drag force, NREL floating type 5 MW wind turbine machine model was built based on OC3-Hywind Spar Buoy platform. Numerical calculation method was applied to floating type wind turbine Spar platform with different number and different thickness plate for dynamic response analysis, in order to obtain amplitude frequency characteristics of the structure movement. The results showed that, along with the increase of heave plate number, the dynamic response of the Spar platform was smaller, the added mass was greater, but its dynamic response was not reduced according to the linear relationship, although it had lower platform dynamic but the effect was not obvious. With the increase of thickness, the added mass of the whole structure would increase, surge RAO and pitching RAO would decrease. Heaving motion abated with the increase of the thick- ness of the plate, however, when the plate thickness increased to 0.4 m, the overall structure of the surge and pitch re- sponse could increase instead.