The effects of structural and aerodynamic nonlinearities on the energy harvesting from airfoil stall-induced oscillations

2019 ◽  
Vol 25 (14) ◽  
pp. 1991-2007 ◽  
Author(s):  
Carlos R. dos Santos ◽  
Flávio D. Marques ◽  
Muhammad R. Hajj
Keyword(s):  
Energy Harvesting ◽  
Degrees Of Freedom ◽  
Electrical Power ◽  
Piezoelectric Element ◽  
Free Play ◽  
Aeroelastic Response ◽  
Wind Speeds ◽  
Aeroelastic Model ◽  
Structural Nonlinearities ◽  
Semi Empirical

An airfoil may undergo stall-induced oscillations beyond the critical flutter speed with amplitudes determined by aerodynamic nonlinearities due to the dynamic stall. Stall-induced oscillations yield intense periodical motions that can be used to convert the airflow energy into electrical power. The inclusion of structural nonlinearities contributes to the complexity of the aeroelastic response. In this sense, the present work models and analyzes for the first time the effects of structural and aerodynamic nonlinearities in the potential of extracting energy from pitching and plunging motions of an airfoil during stall-induced oscillations. A computational model is employed, based on the electro-aeroelastic differential equations modeling a typical aeroelastic section with two degrees of freedom with an electrical generator connected to the pitching motion and a piezoelectric element connected to the plunging motion. The Beddoes–Leishman semi-empirical model is used to represent the unsteady aerodynamic loading. Concentrated structural nonlinearities, such as the hardening effect and free-play, are also considered. Bifurcation diagrams and harvested power calculations are used to analyze the performance of each energy harvesting scheme. The results show that nonlinear pitching stiffness reduces the average harvested power from this degree of freedom in a range of wind speeds. However, the presence of a free-play spring reduces the flutter velocity and initiates the harvesting at lower wind speeds. In conclusion, the present electro-aeroelastic model can be used to find optimal parameters of a harvester from airfoil stall-induced oscillations for a specific application.

scholarly journals Design and Evaluation of Double-Stage Energy Harvesting Floor Tile

2019 ◽  
Vol 11 (20) ◽  
pp. 5582 ◽  
Author(s):  
Isarakorn ◽  
Jayasvasti ◽  
Panthongsy ◽  
Janphuang ◽  
Hamamoto
Keyword(s):  
Energy Harvesting ◽  
Proof Mass ◽  
Electrical Power ◽  
Average Power ◽  
Piezoelectric Element ◽  
Floor Tile ◽  
Cover Plate ◽  
Piezoelectric Cantilever ◽  
Wide Range ◽  
Power And Energy

This paper introduces the design and characterization of a double-stage energy harvesting floor tile that uses a piezoelectric cantilever to generate electricity from human footsteps. A frequency up-conversion principle, in the form of an overshooting piezoelectric cantilever, plucked with a proof mass is utilized to increase energy conversion efficiency. The overshoot of the proof mass is implemented by a mechanical impact between a moving cover plate and a stopper to prevent damage to the plucked piezoelectric element. In an experiment, the piezoelectric cantilever of a floor tile prototype was excited by a pneumatic actuator that simulated human footsteps. The key parameters affecting the electrical power and energy outputs were investigated by actuating the prototype with a few kinds of excitation input. It was found that, when actuated by a single simulated footstep, the prototype was able to produce electrical power and energy in two stages. The cantilever resonated at a frequency of 14.08 Hz. The output electricity was directly proportional to the acceleration of the moving cover plate and the gap between the cover plate and the stopper. An average power of 0.82 mW and a total energy of 2.40 mJ were obtained at an acceleration of 0.93 g and a gap of 4 mm. The prototype had a simple structure and was able to operate over a wide range of frequencies.

Optimization of Energy Harvesting From Stall-Induced Oscillations Using the Multidimensional Kriging Metamodel

2019 ◽  
Vol 14 (7) ◽  
Author(s):  
Carlos R. dos Santos ◽  
Maíra M. da Silva ◽  
Flávio D. Marques
Keyword(s):  
Energy Harvesting ◽  
Electric Energy ◽  
System Of Differential Equations ◽  
Structural Configuration ◽  
Electric Generator ◽  
Wind Speeds ◽  
Potential Source ◽  
Aeroelastic Model ◽  
Kriging Metamodel ◽  
The Moment

The power harvested from stall-induced oscillations of airfoils has been analyzed as a potential source of electric energy for microsystems. Previous works have indicated that the energy harvested from such oscillations is affected by key parameters of the structural configuration. In this sense, this work proposes the optimization of such parameters by considering the use of a stochastic multidimensional Kriging metamodel. The metamodel was built using a database created with simulations of an electro-aeroelastic model. Such model considers aerodynamics loads given by the Beddoes–Leishman model as input for the system of differential equations which governs the pitching motion of an airfoil attached to an electric generator. The results of the optimization process have indicated an optimum point for the elastic axis of the structure and the need for reducing the mass, the moment of inertia, and the stiffness for increasing the harvested power in a range of wind speeds.

Linear and Nonlinear Modeling and Experiments of a Piezoaeroelastic Energy Harvester

2010 ◽  
Author(s):  
Carlos De Marqui Junior ◽  
Marcela de Mello Anice´zio ◽  
Wander G. R. Vieira ◽  
Saulo F. Trista˜o
Keyword(s):  
Energy Harvesting ◽  
Time Domain ◽  
Nonlinear Modeling ◽  
Electrical Power ◽  
Load Resistance ◽  
Free Play ◽  
Degree Of Freedom ◽  
Lumped Parameter Model ◽  
Piezoelectric Energy Harvesting ◽  
Piezoelectric Energy

In this paper a piezoaeroelastically coupled lumped-parameter model for energy harvesting due to flow excitation is presented. A two-dimensional airfoil having two degree of freedom, i.e. pitch and plunge, is investigated. Piezoelectric coupling is considered for the plunge degree of freedom. Therefore an additional electrical degree of freedom is added to the problem. A load resistance is considered in the electrical domain. The unsteady aerodynamic loads are obtained from a time domain lumped vortex model. Two case studies are presented here. First the interaction of piezoelectric energy harvesting and a linear aeroelastic typical section is investigated for a set of electrical load resistances. Time domain responses for pitch and plunge as well as for the electrical outputs (voltage, current and electrical power) are presented. The linear model predictions are compared against experimental results. Later a concentrated nonlinearity (free play) is added to the pitch degree of freedom and the typical section is used to investigate LCO for piezoelectric energy harvesting.

scholarly journals Power-Generation Optimization Based on Piezoelectric Ceramic Deformation for Energy Harvesting Application with Renewable Energy

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2171
Author(s):  
Hyeonsu Han ◽  
Junghyuk Ko
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Energy Harvesting ◽  
Piezoelectric Material ◽  
Lead Zirconate Titanate ◽  
Piezoelectric Ceramic ◽  
Piezoelectric Element ◽  
Piezoelectric Ceramics ◽  
Lead Zirconate ◽  
Piezoelectric Energy

Along with the increase in renewable energy, research on energy harvesting combined with piezoelectric energy is being conducted. However, it is difficult to predict the power generation of combined harvesting because there is no data on the power generation by a single piezoelectric material. Before predicting the corresponding power generation and efficiency, it is necessary to quantify the power generation by a single piezoelectric material alone. In this study, the generated power is measured based on three parameters (size of the piezoelectric ceramic, depth of compression, and speed of compression) that contribute to the deformation of a single PZT (Lead zirconate titanate)-based piezoelectric element. The generated power was analyzed by comparing with the corresponding parameters. The analysis results are as follows: (i) considering the difference between the size of the piezoelectric ceramic and the generated power, 20 mm was the most efficient piezoelectric ceramic size, (ii) considering the case of piezoelectric ceramics sized 14 mm, the generated power continued to increase with the increase in the compression depth of the piezoelectric ceramic, and (iii) For piezoelectric ceramics of all diameters, the longer the depth of deformation, the shorter the frequency, and depending on the depth of deformation, there is a specific frequency at which the charging power is maximum. Based on the findings of this study, PZT-based elements can be applied to cases that receive indirect force, including vibration energy and wave energy. In addition, the power generation of a PZT-based element can be predicted, and efficient conditions can be set for maximum power generation.

Geometric and Material Optimization of Vortex-Induced Vibration Micro Energy Harvesters for Localized Wind Environments

2012 ◽  
Author(s):  
Jesse J. French ◽  
Colton T. Sheets
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Fluid Velocity ◽  
Frequency Variation ◽  
Vortex Induced Vibration ◽  
Energy Harvesters ◽  
Wind Speeds ◽  
Material Optimization ◽  
Piezoelectric Energy ◽  
Wind Velocities

Wind energy capture in today’s environment is often focused on producing large amounts of power through massive turbines operating at high wind speeds. The device presented by the authors performs on the extreme opposite scale of these large wind turbines. Utilizing vortex induced vibration combined with developed and demonstrated piezoelectric energy harvesting techniques, the device produces power consistent with peer technologies in the rapidly growing field of micro-energy harvesting. Vortex-induced vibrations in the Karman vortex street are the catalyst for energy production of the device. To optimize power output, resonant frequency of the harvester is matched to vortex shedding frequency at a given wind speed, producing a lock-on effect that results in the greatest amplitude of oscillation. The frequency of oscillation is varied by altering the effective spring constant of the device, thereby allowing for “tuning” of the device to specific wind environments. While localized wind conditions are never able to be predicted with absolute certainty, patterns can be established through thorough data collection. Sampling of local wind conditions led to the design and testing of harvesters operating within a range of wind velocities between approximately 4 mph and 25 mph. For the extremities of this range, devices were constructed with resonant frequencies of approximately 17 and 163 Hz. Frequency variation was achieved through altering the material composition and geometry of the energy harvester. Experimentation was performed on harvesters to determine power output at optimized fluid velocity, as well as above and below. Analysis was also conducted on shedding characteristics of the device over the tested range of wind velocities. Computational modeling of the device is performed and compared to experimentally produced data.

Effect of Segmented Electrodes on Piezo-Elastic and Piezo-Aero-Elastic Responses of Generator Plates

2009 ◽  
Author(s):  
Carlos De Marqui ◽  
Alper Erturk ◽  
Daniel J. Inman
Keyword(s):  
Electrical Power ◽  
Elastic Behavior ◽  
Elastic Model ◽  
Fe Model ◽  
Aeroelastic Response ◽  
Aerodynamic Model ◽  
Frequency Excitation ◽  
Elastic Responses ◽  
Electrical Power Output ◽  
Tip Mass

In this paper, the use of segmented electrodes is investigated to avoid cancellation of the electrical outputs of the torsional modes in energy harvesting from piezo-elastic and piezo-aero-elastic systems. The piezo-elastic behavior of a cantilevered plate with an asymmetric tip mass under base excitation is investigated using an electromechanically coupled finite element (FE) model. Electromechanical frequency response functions (FRFs) are obtained using the coupled FE model both for the continuous and segmented electrodes configurations. When segmented electrodes are considered torsional modes also become significant in the resulting electrical FRFs, improving broadband (or varying-frequency excitation) performance of the generator plate. The FE model is also combined with an unsteady aerodynamic model to obtain the piezo-aero-elastic model. The use of segmented electrodes to improve the electrical power generation from aeroelastic vibrations of plate-like wings is investigated. Although the main goal here is to obtain the maximum electrical power output for each airflow speed (both for the continuous and segmented electrode cases), piezoelectric shunt damping effect on the aeroelastic response of the generator wing is also investigated.

An analytic study of vibrational energy harvesting using piezoelectric tiles in stairways subjected to human traffic

2018 ◽  
Vol 30 (5) ◽  
pp. 968-985
Author(s):  
CONNOR EDLUND ◽  
SUBRAMANIAN RAMAKRISHNAN
Keyword(s):  
Energy Harvesting ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Random Excitation ◽  
Analytical Models ◽  
Practical Applications ◽  
Type Iii ◽  
Pedestrian Traffic ◽  
Type V ◽  
Vibrational Energy Harvesting

This work investigates analytically, the use of piezoelectric tiles placed on stairways for vibrational energy harvesting – harnessing electrical power from natural vibrational phenomena – from pedestrian footfalls. While energy harvesting from pedestrian traffic along flat pathways has been studied in the linear regime and realised in practical applications, the greater amounts of energy naturally expended in traversing stairways suggest better prospects for harvesting. Considering the characteristics of two types of commercially available piezoelectric tiles – Navy Type III and Navy Type V – analytical models for the coupled electromechanical system are formulated. The harvesting potential of the tiles is then studied under conditions of both deterministic and carefully developed random excitation profiles for three distinct cases: linear, monostable nonlinear and an array of monostable nonlinear tiles on adjacent steps with linear coupling between them. The results indicate enhanced power output when the tiles are: (1) placed on stairways, (2) uncoupled and (3) subjected to excitation profiles with stochastic frequency. In addition, the Navy Type V tiles are seen to outperform the Navy Type III tiles. Finally, the strongly nonlinear regime outperforms the linear one suggesting that the realisation of commercially available piezoelectric tiles with appropriately tailored nonlinear characteristics will likely have a significant impact on energy harvesting from pedestrian traffic.

scholarly journals Electrical power management and optimization with nonlinear energy harvesting structures

2018 ◽  
Vol 30 (2) ◽  
pp. 213-227 ◽  
Author(s):  
Wen Cai ◽  
Ryan L Harne
Keyword(s):  
Energy Harvesting ◽  
Nonlinear Vibration ◽  
Power Management ◽  
Partial Information ◽  
Electrical Power ◽  
System Level ◽  
Vibration Energy ◽  
Amplitude Dependence ◽  
Harvesting Systems ◽  
Nonlinear Energy

In recent years, great advances in understanding the opportunities for nonlinear vibration energy harvesting systems have been achieved giving attention to either the structural or electrical subsystems. Yet, a notable disconnect appears in the knowledge on optimal means to integrate nonlinear energy harvesting structures with effective nonlinear rectifying and power management circuits for practical applications. Motivated to fill this knowledge gap, this research employs impedance principles to investigate power optimization strategies for a nonlinear vibration energy harvester interfaced with a bridge rectifier and a buck-boost converter. The frequency and amplitude dependence of the internal impedance of the harvester structure challenges the conventional impedance matching concepts. Instead, a system-level optimization strategy is established and validated through simulations and experiments. Through careful studies, the means to optimize the electrical power with partial information of the electrical load is revealed and verified in comparison to the full analysis. These results suggest that future study and implementation of optimal nonlinear energy harvesting systems may find effective guidance through power flow concepts built on linear theories despite the presence of nonlinearities in structures and circuits.

Energy Harvesting for Smart Shoes: A Real Life Application

2013 ◽  
Author(s):  
Emanuele Frontoni ◽  
Adriano Mancini ◽  
Primo Zingaretti ◽  
Andrea Gatto
Keyword(s):  
Energy Harvesting ◽  
Power Efficiency ◽  
Indoor Localization ◽  
Electrical Power ◽  
Real Life ◽  
Reducing Power ◽  
Electrical Energy ◽  
General Purpose ◽  
Technical Developments ◽  
Microprocessor Technology

Advanced technical developments have increased the efficiency of devices in capturing trace amounts of energy from the environment (such as from human movements) and transforming them into electrical energy (e.g., to instantly charge mobile devices). In addition, advancements in microprocessor technology have increased power efficiency, effectively reducing power consumption requirements. In combination, these developments have sparked interest in the engineering community to develop more and more applications that utilize energy harvesting for power. The approach here described aims to designing and manufacturing an innovative easy-to-use and general-purpose device for energy harvesting in general purpose shoes. The novelty of this device is the integration of polymer and ceramic piezomaterials accomplished by injection molding. In this spirit, this paper examines different devices that can be built into a shoe, (where excess energy is readily harvested) and used for generating electrical power while walking. A Main purpose is the development of an indoor localization system embedded in shoes that periodically broadcasts a digital RFID as the bearer walks. Results are encouraging and real life test are conducted on the first series of prototypes.

scholarly journals A Spherical Hybrid Triboelectric Nanogenerator for Enhanced Water Wave Energy Harvesting

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 598 ◽  
Author(s):  
Kwangseok Lee ◽  
Jeong-won Lee ◽  
Kihwan Kim ◽  
Donghyeon Yoo ◽  
Dong Kim ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Water Waves ◽  
Water Wave ◽  
Degrees Of Freedom ◽  
Low Frequency ◽  
Random Motion ◽  
Triboelectric Nanogenerator ◽  
Hybrid Energy ◽  
Pollution Levels ◽  
Self Powered

Water waves are a continuously generated renewable source of energy. However, their random motion and low frequency pose significant challenges for harvesting their energy. Herein, we propose a spherical hybrid triboelectric nanogenerator (SH-TENG) that efficiently harvests the energy of low frequency, random water waves. The SH-TENG converts the kinetic energy of the water wave into solid–solid and solid–liquid triboelectric energy simultaneously using a single electrode. The electrical output of the SH-TENG for six degrees of freedom of motion in water was investigated. Further, in order to demonstrate hybrid energy harvesting from multiple energy sources using a single electrode on the SH-TENG, the charging performance of a capacitor was evaluated. The experimental results indicate that SH-TENGs have great potential for use in self-powered environmental monitoring systems that monitor factors such as water temperature, water wave height, and pollution levels in oceans.

Sign in / Sign up

Export Citation Format

Share Document