EAGER: Sediment Transport in the Wake of a Marine HydroKinetic Turbine

EAGER：海洋水力涡轮机后的沉积物输送

• 批准号: 1317382
• 负责人: Anya Jones
• 金额: $ 5.69万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1317382&HistoricalAwards=false
• 关键词: EAGER; Sediment; Transport; Wake; Marine

Marine HydroKinetic (MHK) energy is a largely undeveloped renewable energy source with great potential. Energy recovery from freestream flows such as rivers, tidal passages, and ocean currents may eventually make a significant contribution to U.S. power, but we currently lack understanding of how to recover this energy in an environmentally-safe way. Because of the highly concentrated nature of the resource and the environmental sensitivity of most, if not all, of the high-energy-density sites, successful recovery of MHK energy depends critically on finding answers to the most pressing environmental concerns. Specifically, we do not yet understand how the operation of MHK devices alters the local flow environment and resulting sediment dynamics, nor do we have the methods to quantify these effects. Redistribution of sea floor sediment by the wake of the turbine or its support structure could potentially change the character of the benthic ecosystem. Resuspension of sediment may reintroduce contaminants that had otherwise settled out of the freestream, and the momentum deficit in the wake of the turbine could lead to enhanced deposition. For marine hydrokinetics to become a viable energy resource in the U.S. and the rest of the world, we must understand the environmental effects of these devices.In this EAGER project, Laboratory-scale demonstration experiments will be performed on models of MHK turbines to model the different environments where MHK energy recovery is currently being evaluated. A novel two-phase particle image velocimetry (PIV) technique developed at UMD will be used to quantify the suspended load dynamics of both the carrier fluid and the sediment particles. Bed profiling will be used to assess changes in the local erosion and deposition. The long-term of the PIs is to characterize and quantify the two-phase flow-physics of the interaction between the sea floor geophysical environment and the wake of an MHK turbine, with a specific interest in the redistribution of sediment.Intellectual MeritThe intellectual merit of this work lies in the fundamental nature of non-equilibrium sediment dynamics that occur as a result of a complex flow characterized by high levels of turbulence and vorticity. First, the PIs will quantify the effect of the near wake of a MHK turbine on sediment uplift and transport in laboratory-scale experiments, primarily with the goal to produce demonstration data that illustrates the capabilities and utility of the facility and techniques. Based on the enhanced understanding of the relevant flow-physics gained through these experiments, the PIs will start the initial investigations of the scaling conditions and modeling that will allow the creation of new models for sediment transport induced by MHK flow fields.Broader ImpactsThe broader impacts of this work will extend to both the educational and industrial arenas. The proposed research will enable MHK energy to be assessed in a fair, timely and efficient manner, over a broad range of potential operational sites and conditions. Thus, it could open the doors to a new source that could quickly impact the percentage of renewable energy produced in the United States, displacing non-renewable and polluting sources.

海洋水动力（MHK）能源是一种尚未开发的可再生能源，潜力巨大。从河流、潮汐通道和洋流等自由流中回收能源最终可能会对美国电力做出重大贡献，但我们目前对如何以环境安全的方式回收这种能源缺乏了解。由于资源高度集中的性质以及大多数（如果不是全部）高能量密度地点的环境敏感性，MHK 能源的成功回收关键取决于找到最紧迫的环境问题的答案。具体来说，我们还不了解 MHK 设备的运行如何改变当地的水流环境和由此产生的沉积物动力学，也没有量化这些影响的方法。涡轮机或其支撑结构的尾流引起的海底沉积物的重新分布可能会改变底栖生态系统的特征。沉积物的重新悬浮可能会重新引入原本从自由流中沉淀出来的污染物，而涡轮机尾流中的动量不足可能会导致沉积加剧。 为了使海洋流体动力成为美国和世界其他地区可行的能源，我们必须了解这些设备对环境的影响。在这个 EAGER 项目中，将在 MHK 涡轮机模型上进行实验室规模的演示实验，以模拟目前正在评估 MHK 能量回收的不同环境。 UMD 开发的新型两相粒子图像测速 (PIV) 技术将用于量化载体液体和沉积物颗粒的悬浮负载动态。河床剖面分析将用于评估局部侵蚀和沉积的变化。 PI 的长期目标是表征和量化海底地球物理环境与 MHK 涡轮机尾流之间相互作用的两相流物理，并具有特定的参数。 c 对沉积物重新分布的兴趣。智力价值这项工作的智力价值在于非平衡沉积物动力学的基本性质，这种动力学是由于以高度湍流和涡度为特征的复杂流。 首先，PI 将在实验室规模的实验中量化 MHK 涡轮机的近尾流对沉积物抬升和运输的影响，主要目的是产生演示数据，说明该设施和技术的能力和效用。基于通过这些实验获得的相关“流动物理学”的加深理解，PI 将开始对缩放条件和建模进行初步研究，这将允许创建由 MHK 引起的沉积物传输的新模型更广泛的影响这项工作的更广泛影响将延伸到教育和工业领域。拟议的研究将使 MHK 能源能够在广泛的潜在运营地点和条件下以公平、及时和高效的方式进行评估。因此，它可以打开新能源的大门，这种新能源可以迅速影响美国生产的可再生能源的比例，取代不可再生和污染能源。