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

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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.