Richard Qu
Research Mentor: Michael Bernitsas
Mentor Department: Naval Architecture & Marine Engineering, Engineering
Author(s): Not Available
Session: Session 1 (9:00 AM – 9:50 AM)
Presentation Type: Poster 125
Abstract
Renewable energy, especially horizontal Marine Hydrokinetic (MHK) energy, is everywhere in oceans and rivers and in large quantities. Energy demand grows explosively, but not all the ways to satisfy this demand are sustainable or efficient in independent systems. Developing an efficient and scalable way to tap into hydrokinetic energy will provide a sustainable and reliable power source. In this project, we focused on post-processing experimental data, to better understand the interactions between oscillating cylinders via vortex induced vibrations and galloping. These cylinders harvest energy from water movement. With so many fluid-structure interaction parameters, such as how fluid interacts with the specific structure, lots of data is needed. The data must encompass all the combinations of different parameters that could affect the design. I processed and organized some of this data. More specifically, I graphed data for spring stiffness K=400, for ß=37.5 (adaptive damping factor), with linear damping ratio ? values from .04 to 0.24. Consequently, we learned that some Reynolds numbers result in constructive interference, allowing subsequent cylinders after the first to oscillate more than it would be possible alone, while other values of Reynolds number create destructive interference, and the cylinders don’t oscillate much at all. This is caused by the vortices that shed off the first cylinder. Each cylinder oscillates, affecting the second and subsequent cylinders based on their timing and position, in turn influencing their interaction and how they harvest energy. This research overall helps us better understand how to construct the VIVACE Converter (a UofM patented invention) to optimize these parameters, giving insight on the decision of the cylinder weight and damping based on the flow speed and fluid-structure interactions in desired river and ocean currents. This research is necessary because the parameters must be selected very specifically to optimize the design. In the future, this data will be used to hone the different parts of the VIVACE system to efficiently and sustainably harvest hydrokinetic energy.
