Development of a fully nonlinear, coupled numerical model for assessment of floating tidal stream concepts
Development of a fully nonlinear, coupled numerical model for assessment of floating tidal stream concepts
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DOI：
10.1016/j.oceaneng.2020.108253
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发表时间：
2020-12
影响因子：
5
通讯作者：
S. Brown;E. Ransley;Siming Zheng;N. Xie;B. Howey;D. Greaves
中科院分区：
文献类型：
--
作者：
S. Brown;E. Ransley;Siming Zheng;N. Xie;B. Howey;D. Greaves
与现有的海底安装系统相比，浮动潮汐概念提供了更多的可行地点，以及在自由表面附近收获更高流速的能力。然而，这样的系统将被要求在高能波浪驱动的环境中生存，并且这种系统的性能和生存能力在很大程度上是未知的。目前的工业标准一般使用解耦的数值方法来评估这一问题，但本文提出了一种有效的数值工具的框架，该工具能够预测浮动潮流系统的完全非线性、耦合行为。以OpenFOAM的开源CFD库为基础，以先前开发的计算效率高的涡轮模型为基础，使用通用系统对该框架进行了演示。在线性海浪中单独考虑浮体时，与基于线性位势理论的替代规范的验证结果吻合较好。系统地介绍了系泊力和水轮机模型，表明有必要同时考虑浮动潮汐概念的所有组成部分，与固定装置相比，平台运动和流体流动之间的耦合可以显著增加水轮机负荷的循环幅度。
Compared with existing seabed mounted systems, floating tidal concepts offer an increase in viable sites, along with the ability to harvest higher flow speeds near the free surface. However, such systems will be required to survive in high-energy wave-driven environments, and the performance and survivability of such systems is largely unknown. Current industry standards generally use a decoupled numerical approach to assess this problem, but this paper presents the development of a framework for an efficient numerical tool that is capable of predicting the fully nonlinear, coupled behaviour of floating tidal stream systems. Using the open-source CFD libraries of OpenFOAM as a basis, and a previously developed computationally efficient turbine model, the framework has been demonstrated using a generalised system. Verification against alternative codes based on linear potential theory shows good agreement when the floating structure is considered alone in linear waves. Systematic introduction of mooring forces and the turbine model demonstrates that it is necessary to consider all components of a floating tidal concept simultaneously, and that coupling between platform motion and fluid flow can substantially increase the cyclic amplitude of the turbine loading compared with a fixed device.