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

该方案的重点是理解和控制涡激振动（VIV）从圆柱放置在平面边界附近。本研究的两个直接应用是：(i)在横流环境中保持可能遭受涡激振动的土木结构和机械工程装置的完整性；（ii）利用涡激振动从河流和洋流中收集水动力流体能量。本研究计划的长期目标（10年以上）是阐明与靠近平面边界的圆柱体的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。该项目的愿景是通过理论分析和实验测试的结合，建立对旋涡脱落和VIV的彻底和基本的理解。研究计划可分为两个阶段。第一阶段将通过将相关的流场、几何和模型参数与相关的压力场、漩涡脱落频率和涡激振动状态联系起来，重点了解放置在平面边界附近的圆柱体的涡激脱落和涡激振动。控制无量纲参数将参数化变化，并探讨三维现象的重要性，如模型展弦比和末端效应对涡形成过程的影响。第二阶段的研究是针对漩涡脱落和VIV的特定主题问题。特别是，目标是解释与涡流脱落和涡激振动被动控制相关的基本流动物理，并找到最佳性能标准，以最大化能量提取或最小化结构疲劳。该研究计划的重要实验组成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量诊断设备（粒子图像测速仪、激光多普勒测速仪和力传感器）。未来HQP将获得与流动建模、实验方法、不确定性分析、流动诱发振动以及运动流体和柔性结构之间的能量传递相关的独特实践和理论知识。这些技能可以转移到加拿大的工业应用中，例如可再生能源和民用/海上结构设计。***该研究项目将对靠近平面边界的圆柱体的涡脱落和涡激振动提供基本的见解，并在目标应用中对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.