Efficient Aeroelastic Energy Harvesting From HVAC Ducts

Author(s):  
Xiaokun Ma ◽  
Christopher D. Rahn

Piezoelectric energy harvesters can be used to scavenge energy for unattended sensors in heating ventilation and air conditioning (HVAC) ducts. In this paper, an aeroelastic energy harvester using a pinned-pinned beam is designed, modeled, and analyzed. To obtain the desired model, we use nonlinear Euler-Bernoulli beam theory, a linear piezoelectric constitutive law, and nonlinear pressure dynamics. Compared with the traditional cantilever beam used by previous researchers, the pinned-pinned beam has a higher frequency limit cycle and more efficient mode shape, which ensure higher power output at the same strain level. The pinned-pinned boundary condition also self-limits the response amplitude, limiting strain in the piezoelectric beam and premature failure. Simulation results show that the pinned-pinned beam can harvest at least 4 times more average power than a cantilever beam with the same maximum strain.

2018 ◽  
Vol 211 ◽  
pp. 02009
Author(s):  
Anshul Garg ◽  
Santosha K. Dwivedy

In the present work, a cantilever beam based piezoelectric energy harvester is investigated both theoretically and experimentally. The harvester is consists of a harmonically base excited vertical cantilever beam with a piezoelectric patch at the fixed end and a mass attached at an arbitrary position. The Euler-Bernoulli beam theory is applied considering the cantilever beam to be slender. The temporal nonlinear electromechanical governing equation of motion is obtained by using generalized Galerkin’s method considering two-mode approximation. Here for principal parametric resonance condition the steady state response of the voltage is obtained by using the method of multiple scales. The results are validated by developing an experimental setup of the harvester. For the harvester having a dimension of 295 mm×24 mm×7.6 mm, a maximum voltage of 40 V is obtained for a base motion of 9 mm with a frequency of 10.07 Hz when 15 gm mass is attached at a distance of 140 mm from the fixed end.


Author(s):  
Hichem Abdelmoula ◽  
Abdessattar Abdelkefi

The characteristics and performance of piezoelectric energy harvesters concurrently subjected to galloping and base excitations when using a complex electrical circuit are studied. The considered energy harvester is composed of a bilayered cantilever beam with a square cylindrical structure at its tip. Euler-Bernoulli beam theory, nonlinear quasi-steady hypothesis, and Galerkin method are used to develop a reduced order model of this system. The electrical circuitry of the harvester consists of a load resistance, a capacitance, and an inductance. The impacts of the electrical components of the harvester’s circuitry, the wind speed, and the base excitation frequency and acceleration on the broadband characteristics of the harvester, quenching phenomenon, and appearance of new nonlinear behaviors are deeply investigated and discussed. When both coupled frequencies of electrical and mechanical types exists and are far from each other, it is shown that the quenching phenomenon is only related to the coupled frequency of mechanical type. Unlike the existence of the quenching phenomenon, the results show that the beating phenomenon takes place for different excitation frequencies when they are close to the coupled frequencies of electrical and mechanical types.


Author(s):  
Wei-Jiun Su ◽  
Jean W. Zu

Piezoelectric material has been widely utilized in vibration-based energy harvesters (VEH). The most common configuration of piezoelectric energy harvester is a cantilevered beam with unimorph or bimorph piezoelectric layers. In this paper, a new configuration of PEH is proposed. Two beams are assembled as V shape with tip masses attached. The first beam is a cantilevered beam with tip mass while the second beam is attached to the end of the first beam with a certain angle. Piezoelectric layers are attached to both beams in unimorph configuration for power generation. The analytical solution is derived based on Euler-Bernoulli beam theory. In this analysis, the angle varies from 0 to 135 degree to see the influence of angle on voltage and power frequency response. The V-shaped VEH is proven to have the second resonant frequency relatively close to the first resonant frequency when compared with conventional cantilevered VEH. Furthermore, the angle between the two beams will influence the ratio of the second to the first resonant frequency. By choosing a suitable angle, the V-shaped structure can effectively broaden the bandwidth.


2017 ◽  
Vol 29 (5) ◽  
pp. 800-815 ◽  
Author(s):  
S Srinivasulu Raju ◽  
M Umapathy ◽  
G Uma

Energy harvesting using cantilever-based piezoelectric structure is most popular for harvesting electrical energy from ambient vibrations. Efforts are also made to maximize the harvester power by means of tailoring the structural parameters of the cantilever beam. This article proposes a method to maximize the harvester voltage from the cantilever-based piezoelectric energy harvester by means of tailoring the structure of the cantilever, to have a tapering in width, thickness and in both width and thickness (double taper). It is also proposed to introduce rectangular and trapezoidal cavities in the tapered energy harvesters to further maximize the harvester voltage. The analytical model of the proposed harvesters is developed using Euler–Bernoulli beam theory, and its free vibration solution is analysed using Bessel functions. The energy harvesters are fabricated and experimentally evaluated for its performance. It is concluded from the results of analytical model and experimentation that width, thickness and double-tapered beam increases the harvester voltage by 35.6%, 84.8% and 126.6%, respectively, as compared to the energy harvester designed with uniform cantilever beam. Among all the energy harvesters proposed in this article, the maximum voltage is generated from the double-tapered beam with trapezoidal cavity. The experimental results are in close agreement with the results obtained from the analytical model.


Author(s):  
Saman Farhangdoust ◽  
Claudia Mederos ◽  
Behrouz Farkiani ◽  
Armin Mehrabi ◽  
Hossein Taheri ◽  
...  

Abstract This paper presents a creative energy harvesting system using a bimorph piezoelectric cantilever-beam to power wireless sensors in an IoT network for the Sunshine Skyway Bridge. The bimorph piezoelectric energy harvester (BPEH) comprises a cantilever beam as a substrate sandwiched between two piezoelectric layers to remarkably harness ambient vibrations of an inclined stay cable and convert them into electrical energy when the cable is subjected to a harmonic acceleration. To investigate and design the bridge energy harvesting system, a field measurement was required for collecting cable vibration data. The results of a non-contact laser vibrometer is used to remotely measure the dynamic characteristics of the inclined cables. A finite element study is employed to simulate a 3-D model of the proposed BPEH by COMSOL Multiphasics. The FE modelling results showed that the average power generated by the BPEH excited by a harmonic acceleration of 1 m/s2 at 1 Hz is up to 614 μW which satisfies the minimum electric power required for the sensor node in the proposed IoT network. In this research a LoRaWAN architecture is also developed to utilize the BPEH as a sustainable and sufficient power resource for an IoT platform which uses wireless sensor networks installed on the bridge stay cables to collect and remotely transfer bridge health monitoring data over the bridge in a low-power manner.


Author(s):  
Wei-Jiun Su ◽  
Hsuan-Chen Lu

In this study, a dual-beam piezoelectric energy harvester is proposed. This harvester consists of a main beam and an auxiliary beam with a pair of magnets attached to couple their motions. The potential energy of the system is modeled to understand the influence of the potential wells on the dynamics of the harvester. It is noted that the alignment of the magnets significantly influences the potential wells. A theoretical model of the harvester is developed based on the Euler-Bernoulli beam theory. Frequency sweeps are conducted experimentally and numerically to study the dynamics of the harvester. It is shown that the dual-beam harvester can exhibit hardening effect with different configurations of magnet alignments in frequency sweeps. The performance of the harvester can be improved with proper placement of the magnets.


Author(s):  
Saman Farhangdoust ◽  
Gary Georgeson ◽  
Jeong-Beom Ihn ◽  
Armin Mehrabi

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.


2011 ◽  
Vol 22 (16) ◽  
pp. 1929-1938 ◽  
Author(s):  
S. F. Ali ◽  
M. I. Friswell ◽  
S. Adhikari

This article investigates the possibility of piezoelectric energy harvesters as energy scavenging devices in highway bridges. The structural vibration due to the motion of a load (vehicle) on the bridge is considered as the source of energy generation for the harvester. The energy generated in this way can be useful for wireless sensor networks for structural health monitoring of bridges by reducing or even eliminating the need for battery replacement/recharging. A highway bridge model with a moving point load is investigated and a linear single-degree-of-freedom model is used for the piezoelectric energy harvester. Two types of harvesters, namely, the harvesting circuit with and without an inductor, have been considered and the energy generated for a single vehicle has been estimated. These results may be used, together with traffic statistics, to obtain the variation of average power and thus, for a given application, help to design the energy management system.


2012 ◽  
Vol 24 (2) ◽  
pp. 226-239 ◽  
Author(s):  
Gang Wang

Single-degree-of-freedom lumped parameter model, conventional finite element method, and distributed parameter model have been developed to design, analyze, and predict the performance of piezoelectric energy harvesters with reasonable accuracy. In this article, a spectral finite element method for bimorph piezoelectric beam energy harvesters is developed based on the Timoshenko beam theory and the Euler–Bernoulli beam theory. Linear piezoelectric constitutive and linear elastic stress/strain models are assumed. Both beam theories are considered in order to examine the validation and applicability of each beam theory for a range of harvester sizes. Using spectral finite element method, a minimum number of elements is required because accurate shape functions are derived using the coupled electromechanical governing equations. Numerical simulations are conducted and validated using existing experimental data from the literature. In addition, parametric studies are carried out to predict the performance of a range of harvester sizes using each beam theory. It is concluded that the Euler–Bernoulli beam theory is sufficient enough to predict the performance of slender piezoelectric beams (slenderness ratio > 20, that is, length over thickness ratio > 20). In contrast, the Timoshenko beam theory, including the effects of shear deformation and rotary inertia, must be used for short piezoelectric beams (slenderness ratio < 5).


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