Analysis of Circular Disc and Bimorph Cantilever Beam Energy Harvesters Under Various Constraint Conditions

2021 ◽  
Author(s):  
Kifayat Ullah ◽  
Shahab Khushnood
Keyword(s):  
Cantilever Beam ◽  
Beam Energy ◽  
Circular Disc ◽  
Energy Harvesters

Dynamic Response of Spiral Cantilever Undergoing Magnetic Coupling

2014 ◽  
Vol 14 (08) ◽  
pp. 1440021
Author(s):  
Xiaoling Bai ◽  
Yumei Wen ◽  
Ping Li ◽  
Jin Yang ◽  
Xiao Peng ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Cantilever Beam ◽  
Magnetic Force ◽  
Coupling Effect ◽  
Magnetic Coupling ◽  
Resonant Frequencies ◽  
Energy Harvesters ◽  
Magnetic Transducer ◽  
Underlying Mechanisms ◽  
Tip Mass

Cantilever beams have found intensive and extensive uses as underlying mechanisms for energy transduction in sensors as well as in energy harvesters. In magnetoelectric (ME) transduction, the underlying cantilever beam usually will undergo magnetic coupling effect. As the beam itself is either banded with magnetic transducer or magnets, the dynamic motion of the cantilever can be modified due to the magnetic force between the magnets and ME sensors. In this study, the dynamic response of a typical spiral cantilever beam with magnetic coupling is investigated. The spiral cantilever acts as the resonator of an energy harvester with a tip mass in the form of magnets, and a ME transducer is positioned in the air gap and interacts with the magnets. It is expected that this spiral configuration is capable of performing multiple vibration modes over a small frequency range and the response frequencies can be magnetically tunable. The experimental results show that the magnetic coupling between the magnets and the transducer plays a favorable role in achieving tunable resonant frequencies and reducing the frequency spacings. This will benefits the expansion of the response band of a device and is especially useful in energy harvesting.

Embedded Metamaterial Subframe Patch for Increased Power Output of Piezoelectric Energy Harvesters

2021 ◽  
pp. 1-9
Author(s):  
Saman Farhangdoust ◽  
Gary Georgeson ◽  
Jeong-Beom Ihn ◽  
Armin Mehrabi
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
Renewable Energy Sources ◽  
Piezoelectric Element ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems ◽  
Host Structure ◽  
Self Powered ◽  
Low Efficiency

Abstract These days, piezoelectric energy harvesting (PEH) is introduced as one of the clean and renewable energy sources for powering the self-powered sensors utilized for wireless condition monitoring of structures. However, low efficiency is the biggest drawback of the PEHs. This paper introduces an innovative embedded metamaterial subframe (MetaSub) patch as a practical solution to address the low throughput limitation of conventional PEHs whose host structure has already been constructed or installed. To evaluate the performance of the embedded MetaSub patch (EMSP), a cantilever beam is considered as the host structure in this study. The EMSP transfers the auxetic behavior to the piezoelectric element (PZT) wherever substituting a regular beam with an auxetic beam is either impracticable or suboptimal. The concept of the EMSP is numerically validated, and the COMSOL Multiphysics software was employed to investigate its performance when a cantilever beam is subjected to different amplitude and frequency. The FEM results demonstrate that the harvesting power in cases that use the EMSP can be amplified up to 5.5 times compared to a piezoelectric cantilever energy harvester without patch. This paper opens up a great potential of using EMSP for different types of energy harvesting systems in biomedical, acoustics, civil, electrical, aerospace, and mechanical engineering applications.

scholarly journals Non-linear piezoelectric fluidic energy harvesters: The mutual interaction of two oscillating cylinders

2020 ◽  
Vol 31 (20) ◽  
pp. 2378-2389
Author(s):  
Vahid Azadeh-Ranjbar ◽  
Yi Han ◽  
Niell Elvin ◽  
Yiannis Andreopoulos
Keyword(s):  
Cantilever Beam ◽  
Degrees Of Freedom ◽  
Bluff Body ◽  
Mutual Interaction ◽  
Bluff Bodies ◽  
Velocity Range ◽  
Freestream Velocity ◽  
Energy Harvesters ◽  
Piezoelectric Layers ◽  
Non Linear

The presence of a bluff body upstream of a cantilever beam promotes persistent, aero-elastic vibrations of the beam. Vortex-induced vibration in an array of two mutually interacting bluff bodies in such configurations undergoing two-degrees of freedom transverse oscillation has not been investigated before. In the present work, we have studied experimentally, the unsteady response of an array of two similar rigid cylinders, positioned side-by-side in reference to the freestream velocity, each one mounted on the upstream end of an elastic cantilever beam. By fitting the beams with piezoelectric layers, these configurations are converted to piezoelectric fluid energy harvesters (PFEH) that can extract small amounts of energy from the flow. Comparing the performance of linear (L-PFEH), non-linear (NL-PFEH), and a non-linear array (NLA-PFEH) of harvesters show that NLA-PFEH has the widest broadband operating velocity range and the greatest generated power followed by NL-PFEH and then L-PFEH. The maximum electric power output of NLA-PFEH was ~1000% greater than for NL-PFEH with a corresponding ~250% increase in the operating velocity range. Different cylinder configurations reveal the presence of hysteresis in the behavior of NLA-PFEH when the distance between the cylinders (so-called cylinder gap to diameter ratio), G/ D < 0.5. At large distances from each other ( G/ D ≥ 4), the two cylinders behave like independent, isolated harvester units with rather weak mutual interaction.

A Smart Device for Harnessing Energy From Aerodynamic Flow Fields

2009 ◽  
Author(s):  
Daniel St. Clair ◽  
Christopher Stabler ◽  
Mohammed F. Daqaq ◽  
Jian Luo ◽  
Gang Li
Keyword(s):  
Wind Energy ◽  
Cantilever Beam ◽  
Flow Rate ◽  
Excitation Frequency ◽  
Volumetric Flow Rate ◽  
Smart Device ◽  
Electric Load ◽  
Energy Harvesters ◽  
Air Chamber ◽  
Piezoelectric Cantilever

In this work, inspired by music playing harmonicas, we conduct a conceptual investigation of a coupled aero-electromechanical system for wind energy harvesting. The system consists of a piezoelectric cantilever unimorph structure embedded within an air chamber to mimic the vibration of the reeds in a harmonica when subjected to air flow. In principle, when wind blows into the air chamber, the air pressure in the chamber increases and bends the cantilever beam opening an air path between the chamber and the environment. When the volumetric flow rate of air past the cantilever is large enough, the energy pumped into the structure via the nonlinear pressure forces offset the intrinsic damping in the system setting the beam into self-sustained limit-cycle oscillations. These oscillations induce a periodic strain in the piezoelectric layer which produces a voltage difference that can be channeled into an electric load. Unlike traditional vibratory energy harvesters where the excitation frequency needs to match the resonant frequency of the device for efficient energy extraction, the nonlinearly coupled aero-elasto dynamics of this device guarantees autonomous vibration of the cantilever beam near its natural frequency as long as the volumetric flow rate is larger than a certain threshold. Experimental results are presented to demonstrate the ability of this device to harvest wind energy under normal wind conditions.

Parameter Identification of a Nonlinear Beam Energy Harvester

2012 ◽  
Author(s):  
Dennis J. Tweten ◽  
Brian P. Mann
Keyword(s):  
Parameter Identification ◽  
Harmonic Balance ◽  
Beam Energy ◽  
Restoring Force ◽  
Nonlinear Beam ◽  
Weakly Nonlinear ◽  
Closed Form Solutions ◽  
Energy Harvesters ◽  
Identification Method ◽  
Balance Parameter

This paper describes the application of the harmonic balance parameter identification method to beam energy harvesters. The method is applied to weakly nonlinear and nonlinear, bistable fixed-free piezoelectric beams with tip masses. It is shown that only one measurement is required to identify parameters even though the systems are continuous. In addition, an experimental method of determining the number of restoring force coefficients required to accurately model the systems is presented. The harmonic balance parameter identification method is extended to account for multiple concurrent frequencies in order to identify parameters of weakly nonlinear systems. Finally, parameters are identified for two experimental energy harvesters. Good agreement is shown between the experimental data and the identified parameters using simulations and closed form solutions.

scholarly journals Performance Enhancement of a Multiresonant Piezoelectric Energy Harvester for Low Frequency Vibrations

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2770 ◽  
Author(s):  
Iman Izadgoshasb ◽  
Yee Lim ◽  
Ricardo Vasquez Padilla ◽  
Mohammadreza Sedighi ◽  
Jeremy Novak
Keyword(s):  
Cantilever Beam ◽  
Performance Enhancement ◽  
Low Frequency ◽  
Design Parameters ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Low Frequency Vibration ◽  
External Power Source

Harvesting electricity from low frequency vibration sources such as human motions using piezoelectric energy harvesters (PEH) is attracting the attention of many researchers in recent years. The energy harvested can potentially power portable electronic devices as well as some medical devices without the need of an external power source. For this purpose, the piezoelectric patch is often mechanically attached to a cantilever beam, such that the resonance frequency is predominantly governed by the cantilever beam. To increase the power generated from vibration sources with varying frequency, a multiresonant PEH (MRPEH) is often used. In this study, an attempt is made to enhance the performance of MRPEH with the use of a cantilever beam of optimised shape, i.e., a cantilever beam with two triangular branches. The performance is further enhanced through optimising the design of the proposed MRPEH to suit the frequency range of the targeted vibration source. A series of parametric studies were first carried out using finite-element analysis to provide in-depth understanding of the effect of each design parameters on the power output at a low frequency vibration. Selected outcomes were then experimentally verified. An optimised design was finally proposed. The results demonstrate that, with the use of a properly designed MRPEH, broadband energy harvesting is achievable and the efficiency of the PEH system can be significantly increased.

Effects of Downstream Structures on Aero Elastic Energy Harvesters From Wake-Induced Vibration

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Pakorn Uttayopas ◽  
Chawalit Kittichaikarn
Keyword(s):  
Cantilever Beam ◽  
Polyvinylidene Fluoride ◽  
Bluff Body ◽  
Electrical Energy ◽  
Load Resistance ◽  
High Amplitude ◽  
Triangular Prism ◽  
Energy Harvesters ◽  
Amplitude Vibration ◽  
And Behavior

An upstream cylindrical bluff body connected to a tip body via an aluminum cantilever beam was tested as energy harvester in a wind tunnel. The characteristics and behavior of the different tip body configurations and lengths of aluminum cantilever beam were studied to optimize design to extract wind energy. Particular attention was paid to measure vibration amplitude and frequency response as a function of reduced velocity. Dynamic response showed that the device's behavior was dependent on both tip body shape and cantilever beam length. Flow visualization tests showed that high amplitude vibration was obtainable when a vortex was fully formed on each side of the downstream tip body. This was exemplified in a symmetrical triangular prism tip body at L/D1 = 5, where its structure's vibration frequency was close to its natural frequency. At such configuration, electrical energy was captured using a polyvinylidene fluoride (PVDF) piezoelectric beam of different load resistances, where an optimized load resistance could be found for each Reynolds number. Although power output and efficiency obtained were considerably weak when compared to those of traditional wind turbine, the design merits further research to improve its performance under various circumstances.

Sign in / Sign up

Export Citation Format

Share Document