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

Author(s):  
Michael M. Bernitsas ◽  
Kamaldev Raghavan ◽  
Y. Ben-Simon ◽  
E. M. H. Garcia

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.

Author(s):  
Michael M. Bernitsas ◽  
Kamaldev Raghavan ◽  
Y. Ben-Simon ◽  
E. M. H. Garcia

Any device aiming to harness the abundant clean and renewable energy from ocean and other water resources in the USA must have high energy density, be unobtrusive, have low maintenance, be robust, meet life cycle cost targets, and have a 10–20 year life. The VIVACE (Vortex Induced Vibration Aquatic Clean Energy) Converter — invented by Bernitsas & Raghavan and patented through the University of Michigan — satisfies those criteria. It converts ocean/river current kinetic energy to electricity using VIV successfully and efficiently for the first time. VIVACE is based on the simple 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 two transition regions suppress VIV. Thus, even from currents as slow as 0.25m/sec, VIVACE can extract energy with high efficiency 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 lab prototype are presented. A mathematical model is developed and design particulars for a wide range of application scales are calculated. Experimental measurements on the lab prototype are reported in the sequel paper and used here for preliminary benchmarking.


2021 ◽  
Author(s):  
Luboslav Straka ◽  
Tibor Krenicky

In recent years, there has been an increased emphasis worldwide on the quality of the environment, especially with an orientation towards the application of renewable energy sources. In addition, we are increasingly encountering experimentation aimed at obtaining new green energy sources. One of such sources is biomass. Biomass has been used since the middle ages as a source of heat and light energy. Today, however, we have technologies that allow us to obtain not only heat but also electricity from biomass, or to convert biomass into materials with high energy density and purity. The energy thus transformed can then be used, for example, as a propellant. At the same time, this valuable source of clean energy can be easily transported to the place of consumption. By applying biomass as a source of green energy, we can make a significant contribution to relieving the environment from harmful effects. In recent years, an increased interest in energy obtained from biomass can be observed in Slovakia. Its technical potential is the greatest among other renewable energy sources, and its non-use would essentially be wastage. Therefore, the aim of the paper was to describe two possibilities of transformation of biomass in the form of its energy recovery into the type of energy used for the production of mechanical, thermal and electrical energy. At the same time, in addition to obtaining a suitable form of energy from biomass, another environmental benefit was sought in the form of soil decontamination. In this regard, there is an energetically important crop, which is known under the Latin name Amaranthus caudatus. It is an energy crop that can be grown on slightly contaminated soil with some restrictions. Two methods of energy recovery of this crop were compared. In the first case it was its compaction into briquettes, in the second case it was a process of anaerobic fermentation with subsequent production of biogas. Based on the performed analysis, it was found that these are almost equivalent energy sources. Although both methods of transformation and energy recovery of the green part of Amaranthus caudatus crops have a number of advantages and disadvantages, it can be clearly stated that the positives significantly outweigh the negatives. Therefore, it is recommended to apply this crop as a valuable source of energy for use in real conditions.


RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5432-5443
Author(s):  
Shyam K. Pahari ◽  
Tugba Ceren Gokoglan ◽  
Benjoe Rey B. Visayas ◽  
Jennifer Woehl ◽  
James A. Golen ◽  
...  

With the cost of renewable energy near parity with fossil fuels, energy storage is paramount. We report a breakthrough on a bioinspired NRFB active-material, with greatly improved solubility, and place it in a predictive theoretical framework.


2021 ◽  
Author(s):  
Robert Sprenkle ◽  
Luciano Silvestri ◽  
M. S. Murillo ◽  
Scott Bergeson

Abstract New facilities such as the National Ignition Facility and the Linac Coherent Light Source have pushed the frontiers of high energy-density matter. These facilities offer unprecedented opportunities for exploring extreme states of matter, ranging from cryogenic solid-state systems to hot, dense plasmas, with applications to inertial-confinement fusion and astrophysics. However, significant gaps in our understanding of material properties in these rapidly evolving systems still persist. In particular, non-equilibrium transport properties of strongly-coupled Coulomb systems remain an open question. Here, we study ion-ion temperature relaxation in a binary mixture, exploiting a recently-developed dual-species ultracold neutral plasma. We compare measured relaxation rates with atomistic simulations and a range of popular theories. Our work validates the assumptions and capabilities of the simulations and invalidates theoretical models in this regime. This work illustrates an approach for precision determinations of detailed material properties in Coulomb mixtures across a wide range of conditions.


2018 ◽  
Vol 10 (8) ◽  
pp. 2660 ◽  
Author(s):  
Yi Yuan ◽  
Yingjie Li ◽  
Jianli Zhao

The intermittent and inconsistent nature of some renewable energy, such as solar and wind, means the corresponding plants are unable to operate continuously. Thermochemical energy storage (TES) is an essential way to solve this problem. Due to the advantages of cheap price, high energy density, and ease to scaling, CaO-based material is thought as one of the most promising storage mediums for TES. In this paper, TES based on various cycles, such as CaO/CaCO3 cycles, CaO/Ca(OH)2 cycles, and coupling of CaO/Ca(OH)2 and CaO/CaCO3 cycles, were reviewed. The energy storage performances of CaO-based materials, as well as the modification approaches to improve their performance, were critically reviewed. The natural CaO-based materials for CaO/Ca(OH)2 TES experienced the multiple hydration/dehydration cycles tend to suffer from severe sintering which leads to the low activity and structural stability. It is found that higher dehydration temperature, lower initial sample temperature of the hydration reaction, higher vapor pressure in the hydration reactor, and the use of circulating fluidized bed (CFB) reactors all can improve the energy storage performance of CaO-based materials. In addition, the energy storage performance of CaO-based materials for CaO/Ca(OH)2 TES can be effectively improved by the various modification methods. The additions of Al2O3, Na2Si3O7, and nanoparticles of nano-SiO2 can improve the structural stabilities of CaO-based materials, while the addition of LiOH can improve the reactivities of CaO-based materials. This paper is devoted to a critical review on the development on thermochemical energy storage based on CaO-based materials in the recent years.


Author(s):  
Izham Izzat Ismail ◽  
Norhuda Hidayah Nordin ◽  
Muhammad Hanafi Azami ◽  
Nur Azam Abdullah

A rocket's engine usually uses fuel and oxygen as propellants to increase the rocket's projection during launch. Nowadays, metallic ingredients are commonly used in the rocket’s operation to increase its performance. Metallic ingredients have a high energy density, flame temperature, and regression rate that are important factors in the propulsion process. There is a wide range of additives have been reported so far as catalysts for rocket propulsion. The studies show that the presence of metal additives improves the regression rate, specific impulse and combustion efficiency. Herein, the common energetic additives for rocket propulsion such as metal and light metals are reviewed. Besides the effect of these energetic particles on the regression behaviors of base (hybrid) fuel has been exclusively discussed. This paper also proposed a new alloy namely high entropy alloys (HEAs) as a new energetic additive that can potentially increase the performance of the rocket propellant system.


2015 ◽  
Vol 15 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Saravanan Dhanushkodi ◽  
Vincent H. Wilson ◽  
Kumarasamy Sudhakar

Abstract Cashew nut farming in India is mostly carried out in small and marginal holdings. Energy consumption in the small scale cashew nut processing industry is very high and is mainly due to the high energy consumption of the drying process. The drying operation provides a lot of scope for energy saving and substitutions of other renewable energy sources. Renewable energy-based drying systems with loading capacity of 40 kg were proposed for application in small scale cashew nut processing industries. The main objective of this work is to perform economic feasibility of substituting solar, biomass and hybrid dryer in place of conventional steam drying for cashew drying. Four economic indicators were used to assess the feasibility of three renewable based drying technologies. The payback time was 1.58 yr. for solar, 1.32 for biomass and 1.99 for the hybrid drying system, whereas as the cost-benefit estimates were 5.23 for solar, 4.15 for biomass and 3.32 for the hybrid system. It was found that it is of paramount importance to develop solar biomass hybrid dryer for small scale processing industries.


Author(s):  
Heather Lai ◽  
Chin An Tan ◽  
Yong Xu

Human walking requires sophisticated coordination of muscles, tendons, and ligaments working together to provide a constantly changing combination of force, stiffness and damping. In particular, the human knee joint acts as a variable damper, dissipating greater amounts of energy when the knee undergoes large rotational displacements during walking, running or hopping. Typically, this damping results from the dissipation, or loss, of metabolic energy. It has been proven to be possible however; to collect this otherwise wasted energy through the use of electromechanical transducers of several different types which convert mechanical energy to electrical energy. When properly controlled, this type of device not only provides desirable structural damping effects, but the energy generated can be stored for use in a wide range of applications. A novel approach to an energy harvesting knee joint damper is presented using a dielectric elastomer (DE) smart material based electromechanical transducer. Dielectric elastomers are extremely elastic materials with high electrical permittivity which operate based on electrostatic effects. By placing compliant electrodes on either side of a dielectric elastomer film, a specialized capacitor is created, which couples mechanical and electrical energy using induced electrostatic stresses. Dielectric elastomer energy harvesting devices not only have a high energy density, but the material properties are similar to that of human tissue, making it highly suitable for wearable applications. A theoretical framework for dielectric elastomer energy harvesting is presented along with a mapping of the active phases of the energy harvesting to the appropriate phases of the walking stride. Experimental results demonstrating the energy harvesting capability of a DE generator undergoing strains similar to those experienced during walking are provided for the purpose of verifying the theoretical results. The work presented here can be applied to devices for use in rehabilitation of patients with muscular dysfunction and transfemoral prosthesis as well as energy generation for able-bodied wearers.


2000 ◽  
Vol 18 (2) ◽  
pp. 213-218 ◽  
Author(s):  
M. DUNNE ◽  
J. EDWARDS ◽  
P. GRAHAM ◽  
A. EVANS ◽  
S. ROTHMAN ◽  
...  

The achievement of ignition from an Inertial Confinement Fusion capsule will require a detailed understanding of a wide range of high energy density phenomena. This paper presents some recent work aimed at improving our knowledge of the strength and equation of state characteristics of low-Z materials, and outlines data which will provide quantitative benchmarks against which our predictive radiation hydrodynamics capabilities can be tested. Improvements to our understanding in these areas are required if reproducible and predictable fusion energy production is to be achieved on the next generation of laser facilities.In particular, the HELEN laser at AWE has been used to create a thermal X-ray source with 140 eV peak radiation temperature and 3% instantaneous flux uniformity to allow measurements of the Equation of State of materials at pressures up to 20 Mbar to an accuracy of <±2% in shock velocity. The same laser has been used to investigate the onset of spallation upon the release of a strong shock at a metal-vacuum boundary, with dynamic radiography used to image the spalled material in flight for the first time. Finally, a range of experiments have been performed to generate quantitative radiation hydrodynamics data on the evolution of gross target defects, driven in both planar and imploding geometry. X-ray radiography was used to record the evolving target deformation in a system where the X-ray drive and unperturbed target response were sufficiently characterized to permit meaningful analysis. The results have been compared to preshot predictions made using a wide variety of fluid codes, highlighting substantial differences between the various approaches, and indicating significant discrepancies with the experimental reality. The techniques developed to allow quantitative comparisons are allowing the causes of the discrepancies to be identified, and are guiding the development of new simulation techniques.


2013 ◽  
Vol 700 ◽  
pp. 11-14
Author(s):  
Ai Hong Guo ◽  
Feng Yuan ◽  
Chun Na Zhang ◽  
Wen Bo Su

Lithium-ion secondary cell has high energy density, stable and high working voltage, wide working temperature and long working term. It is a safe and clean energy resource without pollution. At present, Lithium Hexafluorophosphate is used as conducting electrolyte lithium salt in lithium-ion secondary batteries. But Lithium Hexafluorophosphate as conducting electrolyte lithium salt has some disadvantages such as hydrolysis and instability. Lithium Bis (heptafluoroisopropyl) t-etrafluorophosphate Li [(C3F7)2PF4] was received by simons process from diisopropylchlorophosphane in this paper. As electrolyte of Li ion secondary cell, Li [(C3F7)2PF4] had lower vapor pressure than LiPF6 in the solvent in the same temperature, comparable conductivity and oxidation stability in the same concentration in room temperature. It was worth mentioning that Li [(C3F7)2PF4] has excellent stability towards hydrolysis. The synthesis process is safe and easily controlled.


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