CAREER: Experimental studies of turbulent inflow and wake relevant to marine hydrokinetic (MHK) energy conversion

1150797-Wosnik海洋流体动力学（MHK）能量转换，包括潮汐/洋流和波浪能，可能是环境可持续性更高的发电方式之一。 该项目的总体目标是更好地了解湍流流入和尾流在与海洋流体动能转换相关的尺度上的时空结构。一套最先进的实验流体动力学仪器将用于湍流特性，实验室和开放水域（潮汐河口）的测试设施将被使用。本文的研究重点是潮汐能，但其结果也适用于海洋和河流的能量转换以及波浪能。智力优点：MHK能量转换装置受到广泛的湍流尺度。例如，最快的潮流往往出现在水深复杂的地区，这会在MHK设备所在的位置产生复杂的边界层和流动扭曲。初步测试表明，MHK装置的性能以及结构疲劳和失效与湍流密切相关。在下游，MHK装置及其支撑结构产生的湍流会对水柱中的环境和生物产生影响。通常用于开放水域测量的稳健声学多普勒海流剖面仪（ADCP）由于其工作原理而限于低采样率，这导致与MHK设备相关的湍流尺度的空间分辨率不足。另一方面，具有较高时间和空间分辨率的实验技术通常限于实验室环境。在本项目中，首先将在一个大横截面组合式两波水槽中测量湍流流入和流体动力学涡轮机尾流，比较ADCP、多点声学多普勒测速仪（ADV）和水下高帧率粒子图像测速仪（HFR-PIV），以建立每种仪器如何测量时空流结构的基线。然后，湍流流入和流体动力学涡轮机尾流将在开放水域潮汐能试验场进行测量，比较ADCP和ADV。来自实验室和开放水域部署的数据将用于数学建模，采用低维模型和随机估计技术，根据ADCP剖面和ADV参考测量值预测湍流状态。该项目将因此填补一个仪器？规模差距？更广泛的影响：该项目将产生以前无法获得的关于MHK相关流量的时空结构的信息。它将提高我们对MHK环境中不同测量技术的能力的理解，并创建通用预测工具，这将使研究海洋环境中的其他现象和过程成为可能。这项研究的结果将实现更高保真的资源评估和更准确的能量转换设备评估，产生以前无法获得的流体-结构相互作用的流量数据，生成设备阵列布局的数据，促进环境影响评估，并最终改进设计。这将有助于美国？MHK行业要成功。将通过将研究纳入可再生能源和实验流体动力学的高级/研究生课程、作为研究生培训一部分的工业研究机会、外联和继续教育以及参加大学开放日活动、实验室图尔斯参观和演示，实现研究和教育活动的一体化。外联活动将包括与NH海岸科学中心和NH儿童？s博物馆。工程学中代表性不足的群体将通过UNH多样性办公室和学生社团积极招募，作为本科研究人员和潜在的博士研究生从事拟议的研究。学生该项目将用于吸引对可再生能源，流量测量和湍流领域感兴趣的学生，并帮助培训推进这一新行业所需的劳动力。

1150797-WosnikMarine hydrokinetic (MHK) energy conversion, comprised of tidal/ocean current and wave energy, is likely one of the more environmentally sustainable ways to generate electricity. The overall objective of this project is to better understand the spatio-temporal structure of the turbulent inflow and wakes at scales relevant to marine hydrokinetic energy conversion. A suite of state-of-the-art experimental fluid dynamics instrumentation will be employed for turbulence characterization, and both laboratory and open water (tidal estuary) test facilities will be used. The study will focus on tidal energy, however, the results are applicable to ocean and river current energy conversion and wave energy as well. Intellectual Merit: MHK energy conversion devices are subjected to a wide range of turbulent scales. For example, the fastest tidal currents often occur in regions of complex bathymetry, which creates complex boundary layers and flow distortions in locations where MHK devices will be sited. Initial tests have shown that the performance of MHK devices, as well as structural fatigue and failure, are closely linked to turbulence. Downstream, turbulence generated by MHK devices and their support structures can have an effect on the environment and organisms in the water column. The robust Acoustic Doppler Current Profilers (ADCPs) commonly used for open water measurements are limited to low sampling rates due to their operational principle, which results in insufficient spatial resolution for scales of turbulence relevant to MHK devices. On the other hand, experimental techniques with higher temporal and spatial resolution are typically limited to laboratory environments. For this project, turbulent inflow and hydrokinetic turbine wakes will first be measured in a large cross-section combined tow-wave tank comparing ADCPs, multi-point Acoustic Doppler Velocimetry (ADV) and underwater high frame-rate Particle Image Velocimetry (HFR-PIV), to establish baselines on how each instrument measures spatio-temporal flow structures. Then turbulent inflow and hydrokinetic turbine wakes will be measured at an open-water tidal energy test site comparing ADCP and ADV. Data from the laboratory and the open-water deployments will be used in mathematical modeling with low-dimensional model and stochastic estimation techniques to predict turbulent flow states from ADCP profiles and ADV reference measurements. The project will thus fill an instrumentation ?scale gap? that currently exists.Broader Impacts: The project will produce previously unavailable information on the spatio-temporal structure of MHK-relevant flows. It will improve our understanding of the capabilities of the different measurement techniques in an MHK environment and create general predictive tools, which will make possible the study of other phenomena and processes in the marine environment. The results of this research will enable higher-fidelity resource assessment and more accurate energy conversion device evaluation, yield previously inaccessible flow data for fluid-structure interaction, generate data for device array layouts, facilitate environmental impact assessments, and, ultimately, lead to improved designs. It will thus help the United States? MHK industry to become successful. The integration of research and education activities will be achieved through inclusion of research in senior/graduate courses in Renewable Energy and Experimental Fluid Dynamics, industrial research opportunities as part of graduate training, outreach and continuing education, and participation in university open house events, laboratory tours and demonstrations. The outreach will include activities with the NH Seacoast Science Center and the NH Children?s Museum. Underrepresented groups in engineering will be actively recruited through the UNH Office of Diversity and student societies, to work on the proposed research as undergraduate researchers and potential Ph.D. students. The project will be used to attract students interested in the fields of renewable energy, flow measurement and turbulence, and help train the workforce necessary for advancing this new industry.