半潜漂浮式风机垂荡板附加质量研究

Study on Added Mass for Semi-Submersible FloatingOffshore Wind Turbine Heave Plates

半潜漂浮式风机基础往往采用立柱-垂荡板组合结构作为选型型式,这种选型型式的垂荡板附加质量是影响漂浮式风机垂向运动性能的重要参数。以基于边界元法的水动力分析为手段,对半潜漂浮式风机基础垂荡板附加质量的影响因素进行分析与讨论。研究表明:构成半潜漂浮式风机基础多个立柱的垂荡板附加质量彼此之间的干扰较小,并可根据单立柱-垂荡板结构的附加质量推导得到半潜式风机基础的垂向自由度运动整体附加质量。垂荡板-立柱直径比和垂荡板深度的改变都可以调整附加质量,然而从材料成本考虑,改变垂荡板-立柱直径比是较优的选择,最后根据简化计算模型和半潜漂浮式风机的频率设计策略给出了对于初步选型可选择的垂荡板-立柱直径比范围。

The semi-submersible floating offshore wind turbine(FOWT)design frequently employs the combined-column-heave plate structure,therefore,the added mass for the heave plate is crucial to the performance of the FOWT.The boundary element method is applied to the study and discussion on the effects of the heave plate added mass.The study reveals that the column interaction plays subtle effect on the heave plate added mass,and therefore,the vertical motion added mass for the FOWT floating foundation could be derived based on the single column-heave plate structure.Varying the heave plate-column diameter ratio and depth of the heave plate could adjust the heave plate added mass,however,changing heave plate-column diameter ratio is more economical.Finally,based on the simplified calculation model and the frequency design strategy of the semi submersible floating fan,the optional range of the diameter ratio of the heave plate to the column for preliminary selection is provided.