Controlling vortex induced vibrations of cylindrical structures placed near a plane boundary

该建议的重点是了解和控制涡激振动（VIV）从圆柱附近的平面边界。这项研究的两个直接应用是：（i）保持土木结构和机械工程设备的完整性，这些设备可能会在横流环境中发生VIV，以及（ii）利用VIV从河流和洋流中收集流体动力学流体能量。该研究计划的长期目标（10年以上）是阐明与放置在平面边界附近的圆柱体的涡激振动相关的流动物理学，并应用于开发能够增强或抑制涡激振动的全方位被动流动控制装置。该计划的愿景是通过理论分析和实验测试的组合，建立一个彻底的和基本的理解旋涡脱落和涡激振动。研究计划可分为两个阶段。第一阶段的重点是了解涡脱落和涡激振动的圆柱体放置在一个平面边界附近的相关流场，几何形状和模型参数相关的压力场，频率的涡脱落，和涡激振动制度。将改变参数和三维现象的重要性，如模型的长宽比和端部效应对涡流形成过程的影响的无量纲参数。第二阶段的研究是针对特定主题的问题，在涡脱落和涡激振动。特别是，其目标是解释与被动控制旋涡脱落和涡激振动相关的基本流动物理，并找到最佳性能标准，以最大限度地提高能量提取或最小化结构疲劳。该研究计划的重要实验部分将在申请人的运营研究水洞设施中进行，该设施配备了最先进的流动诊断设备（粒子图像测速仪，激光多普勒测速仪和力传感器）。未来的HQP将获得与流动建模，实验方法，不确定性分析，流致振动以及运动流体和柔顺结构之间的能量传递相关的独特实践和理论知识。这些技能可转移到加拿大的行业应用，例如，可再生能源和民用/海上结构设计。

This proposal focuses on understanding and controlling vortex induced vibrations (VIV) from circular cylinders placed near a plane boundary. The two direct applications of this research are: (i) maintaining the integrity of civil structures and mechanical engineering devices which may undergo VIV in a cross-flow environment, and (ii) the harvesting of hydrokinetic fluid energy from rivers and ocean currents using VIV. The long term objective of this research program (10+ years), is to elucidate the flow physics associated with the VIV of circular cylinders placed near a plane boundary with application to developing omni-directional passive flow control devices capable of either enhancing or suppressing VIV. The program vision is to establish a thorough and fundamental understanding of vortex shedding and VIV via a mix of theoretical analysis and experimental testing. The research program can be divided into two phases. Phase I will be focused on understanding the vortex shedding and VIV of circular cylinders placed near a plane boundary by relating the relevant flow field, geometrical, and model parameters to the associated pressure field, frequency of vortex shedding, and VIV regimes. The governing dimensionless parameters will be varied parametrically and the importance of three-dimensional phenomena, such as the effect of model aspect ratio and end effects on the vortex formation process will be explored. Phase II research is targeted towards topic-specific questions in vortex shedding and VIV. In particular, the goal is to explain the fundamental flow physics associated with passive control of vortex shedding and VIV, and find optimal performance criteria to either maximize energy extraction or minimize structural fatigue. The significant experimental component of the research program will be carried out in the applicants operational research water tunnel facility equipped with state-of-the-art flow diagnostic equipment (Particle Image Velocimetry, Laser Doppler Velocimetry, and force sensors). Prospective HQP will receive unique practical and theoretical knowledge related to flow modeling, experimental methods, uncertainty analysis, flow-induced vibrations, and energy transfer between moving fluids and compliant structures. These skills are transferable to industry applications in Canada, e.g., renewable energy and civil/offshore structure design.