非线性混合海况下近海风机塔筒底部载荷的动力响应

本文主要研究在非线性混合海况(即风浪和涌浪组合海况)下,以NREL 5MW_Baseline Monopile近海风机为研究对象,对其塔筒底部(基线)所受到的剪力和弯矩载荷的动力响应进行仿真。在近海风机的时域仿真中,选用了Ochi-Hubble六参数波浪谱,并编制了该谱的程序嵌入到FAST中进行编译。计算过程中,共进行了20次10 min的仿真分析。对于得到的短期载荷,给出了波高程,塔筒底部首尾向剪力和弯矩在线性与非线性不规则波作用下的时程曲线对比图。采用分块最大值法对每一次的短期载荷提取极值,并基于20次仿真所得的极值,给出了塔筒底部首尾向剪力与弯矩在线性与非线性不规则波作用下的超越概率曲线对比图。研究表明,在非线性混合海况下进行近海风机塔筒底部载荷的动力响应研究,计算结果对工程实际应用具有指导意义。

Dynamic response of loads at the baseline of offshore wind turbine tower in nonlinear mixed sea states

In this paper,the NREL 5MW_Baseline Monopile offshore wind turbine is studied in nonlinear mixed sea states(i.e.sea states of combined wind waves and swell),and the dynamic response of the shear and bending moment loads at the baseline of the tower are simulated.In the time-domain simulations of the offshore wind turbine,the Ochi-Hubble sixparameter wave spectrum was selected,and the program of the spectrum was developed and embedded into FAST for compilation.During the calculation,20 simulations of 10 minutes were performed.For the short-term load obtained,we give a comparison of the time-history curves of the wave elevation and the fore-aft tower base shear and the fore-aft tower bending moment at the baseline of the tower under the influence of linear and nonlinear irregular waves.Using the block maximum method to extract the extreme value of each short-term load,and based on the extreme values obtained from the 20 simulations,we give a comparison of the exceedance probability curves of the fore-aft tower base shear and the fore-aft tower bending moment at the baseline of the tower under the influence of linear and nonlinear irregular waves.The research shows that the dynamic response of loads at the baseline of the offshore wind turbine tower in nonlinear mixed sea states,the calculation results have more instructional significance for engineering practice.