Publication Type : Conference Paper
Publisher : Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE
Source : Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, Volume 7, Rotterdam, p.249-260 (2011)
ISBN : 9780791844397
Keywords : Amplitude spectra, Arctic engineering, Aspect ratio, Clean energy, Complex flow structures, Cylinder interference, Cylinders (shapes), Downstream cylinders, Effective tool, Energy availability, Flow-induced motion, High damping, High density, Marine renewable energy, Parameter range, Respiratory mechanics, turbulence, Turbulence controls, Visualization, Vortex induced vibration
Campus : Amritapuri
School : School of Engineering
Department : Mechanical Engineering
Year : 2011
Abstract : The VIVACE (Vortex Induced Vibration for Aquatic Clean Energy) Converter was introduced at OMAE2006 as a single, smooth, circular-cylinder module. The hydrodynamics of VIVACE is being improved continuously to achieve higher density in harnessed hydrokinetic power. Inter-cylinder spacing and Passive Turbulence Control (PTC) through selectively located roughness are effective tools in enhancement of Flow Induced Motions (FIMs) under high damping for power harnessing. VIVACE Converters consist of multi-cylinder modules. Single cylinders harness energy at high density even in 1knot currents. For downstream cylinders questions are raised on energy availability and sustainability of high-amplitude FIM. Through PTC and inter-cylinder spacing, strongly synergetic FIM of 2/3/4 cylinders is achieved, harnessing hydrokinetic energy with increased footprint density. Two-cylinder smooth/PTC and four-cylinder PTC systems are tested experimentally. Using the PTC-to-FIM map developed in previous work at the Marine Renewable Energy Laboratory (MRELab), PTC is applied and cylinder response is measured for the following parameter ranges: In-flow center-to-center distance 1.63•D-5.00•D (D=diameter), transverse center-to-center distance 0.5•D-1.5•D, Re∈ [28,000-120,000], m*∈[1.677-1.690], U∈ [0.36m/s-1.45m/s], aspect ratio l/D=10.29, and m*ζ ∈ [0.0283-0.0346]. All experiments are conducted in the Low Turbulence Free Surface Water (LTFSW) Channel of MRELab. Amplitude spectra and broad filed-of-view (FOV) visualization help reveal complex flow structures and cylinder interference undergoing VIV, interference/ proximity/wake/soft/hard galloping. Copyright © 2011 by ASME.
Cite this Research Publication : E. Sa Kim, Bernitsas, M. Mbc, and Kumar, R. Abd, “Multi-cylinder Flow-Induced Motions: Enhancement by Passive Turubulence Control at 28,000