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

这一建议的重点是理解和控制位于平面边界附近的圆柱体的涡激振动。这项研究的两个直接应用是：(I)保持土木工程结构和机械工程设备在横流环境中可能发生涡旋的完整性，以及(Ii)利用涡流从河流和洋流中获取流体动能。这一研究计划的长期目标(10年以上)是为了阐明与平面边界附近圆柱涡激振动相关的流动物理，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相结合的方式，建立对涡流脱落和涡激振动的透彻和基本的理解。研究计划可分为两个阶段。第一阶段将侧重于通过将相关的流场、几何参数和模型参数与相关的压力场、涡脱落频率和涡激状态联系起来，来了解放置在平面边界附近的圆柱体的涡脱和涡激振动。控制无量纲参数将随参数变化，并将探讨三维现象的重要性，如模型展弦比和端部效应对旋涡形成过程的影响。第二阶段的研究针对涡旋脱落和涡旋涡旋的特定主题问题。特别是，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，并找到最优性能标准，以最大化能量提取或最大限度地减少结构疲劳。研究计划的重要实验部分将在申请者操作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、流动诱导振动以及运动流体和柔顺结构之间的能量传递有关的独特实践和理论知识。这些技能可以转移到加拿大的工业应用中，例如可再生能源和土木/海上结构设计。 该研究计划将对位于平面边界附近的圆柱体的涡流脱落和涡激振动提供基本的见解，并对有针对性的应用中的替代能量收集装置和工程结构的设计产生重大影响。

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. The research program will contribute fundamental insights into the vortex shedding and vortex induced vibrations of circular cylinders placed near a plane boundary, and have a significant impact on the design of alternative energy harvesting devices and engineering structures in targeted applications.