畸形波作用下Spar浮式风机平台运动响应预报的高效细长体模型方法研究

The wind energy exploration in deep-water field is an inevitable trend for offshore wind power development of our country. According to foreign exploiting experience, it is indicated that Spar wind turbines can be applied in deep-water regions. However, freak waves being in deep sea have posed severer threat to Spar wind turbines. If their motion responses could be predicted quickly and accurately in advanced and their positions and attitudes can be actively controlled, the capsizal disaster can be avoided. So far the similar studies are hardly found in publications; additionally the current predicting methods are mainly used for regular waves and random waves, or based on linear/weakly linear theory between waves and floating structures, or needs expensive computing costs. Therefore, an efficient method has to be developed to realize actively controlling motions of Spar wind turbines. Firstly, this project improves the efficiency of freak wave generating scheme and successfully produces freak waves，especially for large-steepness freak waves. Then, different calculating schemes of slender model will be investigated, to develop advanced slender model for motion response prediction of Spar wind turbines under freak waves. Finally, the newly-developed slender model and the one usually adopted by offshore engineering design are verified by fully nonlinear potential theory, mechanics of viscous fluids and physical model tests and their applicable criterions are clarified. This research conclusion can be considered as a technique storage for disaster prevention of Spar wind turbines under freak waves in deep-water field.

我国海上风电开发由浅水转向深水已成为未来发展的必然趋势。国外已有开发经验表明可采用Spar浮式风机，然而深水海域的畸形波严重威胁Spar风机的安全，需要发展一种运动响应高效预报方法，实现对Spar风机运动响应的主动控制，避免倾覆灾难发生。然而目前对于畸形波海况下Spar风机运动响应的预报鲜有研究，现有预报方法主要针对规则波和随机波工况，或基于线性/弱非线性波物相互作用理论，或预报时间较长。本项目首先研究获得畸形波尤其是大波陡畸形波的有效生成方法，生成小/大波陡畸形波，然后揭示细长体模型法中各因素对其运动响应预报结果精度和效率的作用规律，开发出畸形波作用下Spar风机平台运动响应预报的高效细长体模型方法，最后综合全非线性势流、粘性流体力学计算及模型试验，探明所开发细长体模型法及工程设计细长体模型法的适用判据。完成上述研究可为深水Spar风机在畸形波海况下的主动防灾、减灾提供技术储备。

我国深水海上风能资源优质且储量大，目前尚未被开发且相关风电装备技术储备不足，已有研究初步表明Spar浮式风机可用于深水风电资源开发。本项目首先对现有畸形波的生成方法进行研究，考察得畸形波的时间与空间参数、波幅及波浪幅值谱对畸形波的作用规律及定量估算公式，可用于指导物理/数值水池中畸形波浪的有效模拟。其后开发畸形波作用下Spar浮式风机平台运动响应预报的细长体模型方法，获得具有不同精度水平的运动响应预报方法，经物理模型试验校核，本项目所开发的细长体模型方法可用于Spar浮式风机的开发与设计中。