Lieber Lilian, Fraser Shaun, Coles Daniel, Nimmo-Smith W Alex M
Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK.
School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.
Nat Commun. 2024 Sep 20;15(1):8244. doi: 10.1038/s41467-024-52578-x.
Ocean energy extraction is on the rise. While tides are the most predictable amongst marine renewable resources, turbulent and complex flows still challenge reliable tidal stream energy extraction and there is also uncertainty in how devices change the natural environment. To ensure the long-term integrity of emergent floating tidal turbine technologies, advances in field measurements are required to capture multiscale, real-world flow interactions. Here we use aerial drones and acoustic profiling transects to quantify the site- and scale-dependent complexities of actual turbulent flows around an idled, utility-scale floating tidal turbine (20 m rotor diameter, D). The combined spatial resolution of our baseline measurements is sufficiently high to quantify sheared, turbulent inflow conditions (reversed shear profiles, turbulence intensity >20%, and turbulence length scales > 0.4D). We also detect downstream velocity deficits (approaching 20% at 4D) and trace the far-wake propagation using acoustic backscattering techniques in excess of 30D. Addressing the energy-environment nexus, our oceanographic lens on flow characterisation will help to validate multiscale flow physics around offshore energy platforms that have thus far only been simulated.
海洋能源开采正在兴起。虽然潮汐是海洋可再生资源中最可预测的，但湍急复杂的水流仍然对可靠的潮流能开采构成挑战，而且设备如何改变自然环境也存在不确定性。为确保新兴浮动式潮汐涡轮机技术的长期完整性，需要在现场测量方面取得进展，以捕捉多尺度的实际水流相互作用。在此，我们使用无人机和声学剖面测量来量化一台闲置的、公用事业规模的浮动潮汐涡轮机（转子直径D = 20米）周围实际湍流的场地和尺度依赖性复杂性。我们基线测量的综合空间分辨率足够高，能够量化剪切湍流流入条件（反向剪切剖面、湍流强度>20%以及湍流长度尺度>0.4D）。我们还检测到下游速度亏缺（在4D处接近20%），并使用声学反向散射技术追踪超过30D的远尾流传播。针对能源与环境的关系，我们从海洋学角度对水流特征进行描述，将有助于验证迄今为止仅通过模拟研究的海上能源平台周围的多尺度水流物理特性。
