VIVACE (Vortex Induced Vibration Aquatic Clean Energy): A New Concept in Generation of Clean and Renewable Energy From Fluid Flow

Abstract

Any device aiming to harness the abundant clean and renewable energy from ocean and other water resources must have high energy density, be unobtrusive, have low maintenance, be robust, meet life cycle cost targets, and have a 10–20year life. The vortex induced vibration aquatic clean energy (VIVACE) converter—invented by Bernitsas and Raghavan, patent pending through the University of Michigan—satisfies those criteria. It converts ocean/river current hydrokinetic energy to a usable form of energy such as electricity using VIV successfully and efficiently for the first time. VIVACE is based on the idea of maximizing rather than spoiling vortex shedding and exploiting rather than suppressing VIV. It introduces optimal damping for energy conversion while maintaining VIV over a broad range of vortex shedding synchronization. VIV occurs over very broad ranges of Reynolds (Re) number. Only three transition regions suppress VIV. Thus, even from currents as slow as 0.25m∕s, VIVACE can extract energy with high power conversion ratio making ocean/river current energy a more accessible and economically viable resource. In this paper, the underlying concepts of the VIVACE converter are discussed. The designs of the physical model and laboratory prototype are presented. A mathematical model is developed, and design particulars for a wide range of application scales are calculated. Experimental measurements on the laboratory prototype are reported in the sequel paper and used here for preliminary benchmarking.

Experimental Investigation on Soft Galloping and Hard Galloping of Triangular Prisms

“…where m o is the original mass of the oscillation system, which is the sum of prism mass m pri , mass of transmission m tra , and one-third of the spring mass m spr [23].…”

“…N and M denote the total numbers of the upper extensional springs and the lower extensional springs. m d is the displaced mass of the prism [23]. where kui and klj denote the stiffness of the ith upper extensional spring and jth the lower extensional spring, respectively.…”

Akiş Kaynakli Ti̇treşi̇mde İki̇ Ardişik Si̇li̇ndi̇rden Elde Edi̇len Gücün Parametri̇k Olarak İncelenmesi̇

“…To convert hydrokinetic energy to mechanical energy and subsequently electrical energy, additional damping is used in the system. The total damping (C total ) is defined as total structure harness C C C  (2) Where C stucture is the existing damping due to losses in the transmission system, in this research, all the C stucture are adjusted by V ck system according to m* and K to achieve same artificial  structure , C stucture is the damping added through V ck that converts the mechanical energy in the oscillating cylinder to electrical energy simulating the real flow.…”

Numerical Investigation on Vortex-Induced Vibration Energy Extraction Efficiency of Double Circular Cylinders In Tandem Arrangement at Low Reynolds Number

“…However, based on vortex-induced vibration (VIV), renewable energy can be harvested from the flow water at low velocity, which has caused abroad attention in recent years. Bernitsas proposed a single cylinder converter which harvesting energy from water flow based on VIV in the Marine Renewable Energy Laboratory (MRELab) at the University of Michigan [3,4]. The effects of high damping and high Reynolds number were researched, and the highest efficiency of energy con-version and the corresponding damping value were found (the converter was at a speed between 0.4m/s and 1.1m/s and the spring stiffness between 400N/m and 1800N/m).…”