FloWTurb: Response of Tidal Energy Converters to Combined Tidal Flow, Waves, and Turbulence

众所周知，潮流具有复杂的湍流结构。虽然潮汐的大小和方向变化是确定的，但波浪流环境中湍流的特征在本质上是随机的，而且还没有得到很好的理解。环境上游湍流强度影响潮汐能水轮机的性能，同时影响下游尾流的形成；后者在规划潮汐涡轮机阵列时至关重要。当波浪加入到汹涌的潮汐流中时，由此产生的波浪流诱导的湍流及其对潮汐涡轮机的影响使设计问题真正具有挑战性。虽然在世界各地的几个地点获得了一些非常有趣和有用的潮汐湍流现场测量结果，但只有在波浪和潮流共存的地方进行了有限的测量，例如在PFOW。此外，由于这些测量是在授权给特定海洋能源设备开发商的地点进行的，因此学术研究人员或其他设备开发商无法访问这些数据。鉴于Pentland Firth潮汐流发电的持续发展，迫切需要在计划设备部署附近的位置进行先进的现场测量。同样，在实验室中控制波浪、电流和湍流的产生，以及模型级潮汐涡轮机性能特征的测量，将有助于进一步理解波浪-电流相互作用。这样的测量将提供一个正确的理解波浪和不对齐的潮汐流对潮汐涡轮机性能的综合影响，以及由此产生的单个设备和完整阵列的循环负荷。这些测量的可用性将减少分析中的不确定性（从而降低风险），从而通过更优化的潮汐涡轮机叶片和转子结构的明智设计提高可靠性（从而降低成本）。了解波浪-电流-结构相互作用及其对转子、支撑结构、基础和其他结构部件的动态载荷的影响，不仅对于功率或性能的评估至关重要，而且对于用于评估该技术的生存能力和经济可行性的正常操作和极端波浪和当前情景的估计至关重要，并预测相关风险。该提案旨在通过实验室和实地测量来解决这些问题。本研究将探讨潮流、重力波和环境湍流对潮汐能转换器动态响应的综合影响。将建立一个高质量的数据库，包括Pentland Firth、Orkney水域和Shetland地区的现场测量数据，并辅以爱丁堡大学FloWave波流设备的实验室测量数据。控制实验将在爱丁堡大学的FloWave设施进行，以确定潮汐装置上的水动力载荷，从而参数化波浪-电流-湍流引起的涡轮转子和基础上的疲劳载荷。

Tidal currents are known to have complex turbulent structures. Whilst the magnitude and directional variation of a tidal flow is deterministic, the characteristics of turbulent flow within a wave-current environment are stochastic in nature, and not well understood. Ambient upstream turbulent intensity affects the performance of a tidal turbine, while influencing downstream wake formation; the latter of which is crucial when arrays of tidal turbines are planned. When waves are added to the turbulent tidal current, the resulting wave-current induced turbulence and its impact on a tidal turbine make the design problem truly challenging. Although some very interesting and useful field measurements of tidal turbulence have been obtained at several sites around the world, only limited measurements have been made where waves and tidal currents co-exist, such as in the PFOW. Also, as these measurements are made at those sites licensed to particular marine energy device developers, the data are not accessible to academic researchers or other device developers. Given the ongoing development of tidal stream power in the Pentland Firth, there is a pressing need for advanced in situ field measurements at locations in the vicinity of planned device deployments. Equally, controlled generation of waves, currents and turbulence in the laboratory, and measurement of the performance characteristics of a model-scale tidal turbine will aid in further understanding of wave-current interactions. Such measurements would provide a proper understanding of the combined effects of waves and misaligned tidal stream flows on tidal turbine performance, and the resulting cyclic loadings on individual devices and complete arrays. The availability of such measurements will reduce uncertainty in analysis (and hence risk) leading to increased reliability (and hence cost reductions) through the informed design of more optimised tidal turbine blades and rotor structures. An understanding of wave-current-structure interaction and how this affects the dynamic loading on the rotor, support structure, foundation, and other structural components is essential not only for the evaluation of power or performance, but also for the estimation of normal operational and extreme wave and current scenarios used to assess the survivability and economic viability of the technology, and to predict associated risks. The proposal aims to address these issues through laboratory and field measurements. This research will investigate the combined effect of tidal currents, gravity waves, and ambient flow turbulence on the dynamic response of tidal energy converters. A high quality database will be established comprising field-scale measurements from the Pentland Firth, Orkney waters, and Shetland region, supplemented by laboratory-scale measurements from Edinburgh University's FloWave wave-current facility. Controlled experiments will be carried out at Edinburgh University's FloWave facility to determine hydrodynamic loads on a tidal current device and hence parameterise wave-current-turbulence-induced fatigue loading on the turbine's rotor and foundation.