带月池驳船式浮式风力机水动力性能

Hydrodynamic Performance of a Barge-Type Floating Offshore Wind Turbine with Moonpool

参考Ideol-Floatgen相关设计,对带月池驳船式浮式风力机进行频域水动力性能研究,考虑了月池黏性阻尼的修正.首先对月池的共振模态进行分析,计算风力机在规则波下的水动力系数与不规则波下运动响应谱,并结合DNV相关规范对风力机的安全性进行了评估.结果表明,在作业工况与生存工况下,浮式风力机的动态纵倾与机舱加速度均符合安全性要求.通过对驳船式浮式风力机运动与月池共振的耦合作用的研究,发现风力机的运动会引起月池活塞共振频率的偏移与活塞共振幅值的减小,晃荡共振的频率基本不受影响,但一阶晃荡共振的幅值会增大.与无月池驳船式浮式风力机相比,月池可以降低风力机整体的运动响应,提升风力机整体的水动力性能.对浮式风力机驳船式平台的边长、月池边长与平台吃水进行参数化分析,将风力机的纵荡、垂荡、纵摇响应均方根(RMS)值与机舱加速度响应RMS值作为对比的指标,发现平台边长的增加可以有效降低风力机在作业工况与生存工况下的4项响应RMS值;月池边长的增加可以大幅降低平台生存工况下的4项响应RMS值;平台吃水的增加可以显著降低风力机在作业工况下的4项响应RMS值,并提高生存工况下的垂荡与纵摇响应RMS值.

The hydrodynamic performance of a barge-type floating offshore wind turbine(FOWT)with a moonpool is studied in frequency domain with reference to the Ideol-Floatgen design.The correction of the viscous damping of the moonpool is considered.First,the resonance modes of the moonpool are analyzed.Then,the hydrodynamic coefficients of the FOWT under regular waves and the motion responses under irregular waves are investigated.Finally,the safety of the FOWT is verified with respect to the DNV standards.The results show that the dynamic pitch and nacelle acceleration of the barge-type FOWT meet the safety requirements under both operating and survival conditions.The investigation of the coupling effects of the platform motion and the moonpool resonance shows that the motion of the platform will cause the shift of the piston mode frequency of the moonpool and the reduction of the piston mode response amplitude,the frequency of the sloshing mode is basically unaffected,but the response amplitude of the first-order sloshing mode is increased.The motion responses of the barge-type FOWT with and without the moonpool are compared.It is found that the moonpool can reduce the motion response of the FOWT,and improve the overall hydrodynamic performance of the FOWT.The platform length,moonpool length and platform draught are parametrically analyzed.Surge,heave,pitch response RMS values and the nacelle acceleration response RMS value are used as the indicators of comparison.It is found that the increase of the platform length could effectively reduce the four response RMS values of the FOWT under both operating and survival conditions,the increase of the moonpool length will reduce the four response RMS values of the FOWT under the operating condition,and the increase of the platform draught could significantly reduce the four response RMS values of the FOWT under the survival condition,the heave and pitch response RMS values increase with the augmentation of the draught under the operating condition.