scholarly journals Enhancing Output Power of a Cantilever-Based Flapping Airflow Energy Harvester Using External Mechanical Interventions

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1499 ◽  
Author(s):  
Liuqing Wang ◽  
Dibin Zhu
Keyword(s):  
Flow Velocity ◽  
Output Power ◽  
Cantilever Beam ◽  
Power Output ◽  
Bluff Body ◽  
Energy Harvester ◽  
Magnetic Interaction ◽  
Electrical Energy ◽  
Increase Flow Velocity ◽  
Electrical Damping

This paper presents a flapping airflow energy harvester based on oscillations of a horizontal cantilever beam facing the direction of airflow. A wing is attached to the free end of a cantilever beam and a bluff body is placed in front of the wing from where vortex falls off, producing vortices under the wing and driving it to oscillate. An electromagnetic transducer is integrated to convert the flow induced vibration into electrical energy. This flapping energy harvester, however, may stop oscillating or vibrate in the second mode under high electrical damping, and thus may be unable to achieve its optimum performance. Simple yet effective mechanical interventions can be applied to the harvester to enhance its power output, i.e., to increase flow velocity and to apply external magnetic interaction. The effect of airflow velocities on output power was investigated experimentally and the results show that the energy harvester scavenges more power in airflow at higher Reynolds numbers (higher flow velocity at R e < 24,000). The external magnetic excitation is achieved though placing one magnet to the wing and another one above the wing to induce a repelling force, aiding the beam to oscillate in high electrical damping. Experimental results show that the power output can be enhanced by 30% when the magnet interaction is properly integrated.

scholarly journals Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Output Voltage ◽  
Energy Harvester ◽  
Load Resistance ◽  
Engineering Practice ◽  
Maximum Output ◽  
Widespread Application ◽  
Piezoelectric Energy ◽  
Axial Excitation

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.

A Complete System Modelling of Piezoelectric Energy Harvester (PEH) with Silicon Carbide (SiC) Used as Cantilever Base

2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Mohd Nor Fakhzan Mohd Kazim ◽  
Selvanayakan Raman ◽  
Muhammad Hafiz Shafie ◽  
Nashrul Fazli Mohd Nasir ◽  
Asan Gani Abdul Muthalif
Keyword(s):  
Silicon Carbide ◽  
Output Power ◽  
Energy Harvester ◽  
Damping Ratio ◽  
Electrical Energy ◽  
System Modelling ◽  
Electronic Circuitry ◽  
Piezo Element ◽  
Piezoelectric Energy ◽  
Sic Wafer

Silicon carbide (SiC) is a material that possesses hardness and robustness to operate under high temperature condition. This work is a pilot in exploring the feasibility of cubic piezo element on the SiC wafer with integrated proof mass as horizontal cantilever with perpendicular displacement with respect to the normal plane. With the advance of electronic circuitry, the power consumption is reduced to nano-watts. Therefore, harvesting ambient energy and converting into electrical energy through piezoelectric material will be useful for powering low power devices. Resonance is a property which able to optimize the generated output power by tuning the proof masses. The damping ratio is a considerable parameter for optimization. From analytical study, small damping ratio will enhance the output power of the piezoelectric energy harvester (PEH). This paper will present mathematical modelling approach, simulation verification and the conditional circuit named versatile precision full wave rectifier.  

Design and Analysis of a Hybrid Solar and Vibration Energy Harvester

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
M Shafiqur Rahman ◽  
Uttam K. Chakravarty
Keyword(s):  
Solar Radiation ◽  
Cantilever Beam ◽  
Power Output ◽  
Energy Harvester ◽  
High Efficiency ◽  
Photovoltaic System ◽  
Small Scale ◽  
Power Calculation ◽  
Hybrid Energy ◽  
Harvesting Technique

AbstractThe performance of the small-scale stand-alone energy harvesters can be improved by implementing a hybrid energy harvesting technique. This paper aims at presenting the design and characterization of a hybrid energy harvester that can simultaneously harvest energy from mechanical vibration and solar radiation by combining piezoelectric, electromagnetic, electrostatic, and photovoltaic mechanisms. The hybrid device consists of a small high-efficiency solar panel and a bimorph PZT cantilever beam having a cylindrical tip magnet and two sets of capacitors (comb electrodes) attached on two sides of an ASTM 6061 T-6 Aluminum substrate. All the transducing sections of the configuration are interconnected by a smart hybrid electric circuit having a common optimum load resistance, an energy storage, and a microcontroller to generate and store combined power output when subjected to transverse vibration and solar radiation. The initial bias-voltage input required for the electrostatic mechanism is either obtained from the photovoltaic system or taken from the storage through the microcontroller. Results for the maximum power output are obtained at the fundamental resonance frequency of the vibrating cantilever beam. As the hybrid design allows a combined power harvesting method, more power is generated with better conversion efficiency than those obtained by stand-alone mechanisms. In addition to the power calculation, the study includes a stress and fatigue analysis of the cantilever beam using the finite element method to investigate the stress-life criteria of the hybrid structure.

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.

scholarly journals Potential of Micro Hydroelectric Generator Embedded at 30,000 PE Effluent Discharge of Sewerage Treatment Plant

2018 ◽  
Vol 34 ◽  
pp. 02037 ◽  
Author(s):  
M.A. Che Munaaim ◽  
N. Razali ◽  
A. Ayob ◽  
N. Hamidin ◽  
M.A. Othuman Mydin
Keyword(s):  
Output Power ◽  
Power Output ◽  
Electricity Generation ◽  
Electrical Power ◽  
Treatment Plant ◽  
Electrical Energy ◽  
Payback Period ◽  
Flowing Water ◽  
Hydroelectric Generator ◽  
Effluent Discharge

A micro hydroelectric generator is an energy conversion approach to generate electricity from potential (motion) energy to an electrical energy. In this research, it is desired to be implemented by using a micro hydroelectric generator which is desired to be embedded at the continuous flow of effluent discharge point of domestic sewerage treatment plant (STP). This research evaluates the potential of electricity generation from micro hydroelectric generator attached to 30,000 PE sewerage treatment plant. The power output obtained from calculation of electrical power conversion is used to identify the possibility of this system and its ability to provide electrical energy, which can minimize the cost of electric bill especially for the pumping system. The overview of this system on the practical application with the consideration of payback period is summarized. The ultimate aim of the whole application is to have a self-ecosystem electrical power generated for the internal use of STP by using its own flowing water in supporting the sustainable engineering towards renewable energy and energy efficient approach. The results shows that the output power obtained is lower than expected output power (12 kW) and fall beyond of the range of a micro hydro power (5kW - 100kW) since it is only generating 1.58 kW energy by calculation. It is also observed that the estimated payback period is longer which i.e 7 years to recoup the return of investment. A range of head from 4.5 m and above for the case where the flow shall at least have maintained at 0.05 m3/s in the selected plant in order to achieved a feasible power output. In conclusion, wastewater treatment process involves the flowing water (potential energy) especially at the effluent discharge point of STP is possibly harvested for electricity generation by embedding the micro hydroelectric generator. However, the selection of STP needs to have minimum 4.5 meter head with 0.05 m3/s of continuously flowing water to make it feasible to harvest.

Hydrokinetic Vortex Induced Vibration (VIV) Energy Harvester

2020 ◽  
Author(s):  
Xiaoyu Zhou ◽  
Vesselina Roussinova ◽  
Vesselin Stoilov
Keyword(s):  
Bluff Body ◽  
Energy Harvester ◽  
Electrical Energy ◽  
Average Frequency ◽  
Flow Speed ◽  
Peak Amplitude ◽  
Low Flow ◽  
Bluff Bodies ◽  
Vortex Induced Vibration ◽  
Low Speed

Abstract This paper investigates the performance of vortex-induced vibration (VIV) energy harvester in low-speed water flow. The proposed VIV harvester is extracting hydrokinetic energy from the flowing current and transferring it into mechanical vibrations. The vibrations are further converted into electrical energy using the piezoelectric transducer to supply the modern demand for energy-consumption. To meet the demand, the single harvester is analyzed to determine the suitable geometry for the bluff body that is sensitive to the low-speed flow. Furthermore, the converter must be able to harvest vibrations of varying amplitudes and frequencies. To maximize the power output, different array configurations of multiple bluff bodies are examined. A single positively buoyant elastically mounted cylinder is tested experimentally and at a low flow speed of 0.3 m/s, it can harvest vibrations with an average frequency of 1.8 Hz and peak to peak amplitude of 1.5d, where d is the diameter of the bluff body. It was found that for an array consisting of ten bluff bodies, the average frequency and peak to peak amplitude increases to 2.09Hz and 1.54d, respectively.

A self-tunable wind energy harvester utilising a piezoelectric cantilever beam with bluff body under transverse galloping for field deployment

2021 ◽  
Vol 245 ◽  
pp. 114559
Author(s):  
Yee Yan Lim ◽  
Ricardo Vasquez Padilla ◽  
Andreas Unger ◽  
Rodrigo Barraza ◽  
Ahmed Mostafa Thabet ◽  
...  
Keyword(s):  
Wind Energy ◽  
Cantilever Beam ◽  
Bluff Body ◽  
Energy Harvester ◽  
Piezoelectric Cantilever ◽  
Field Deployment ◽  
Transverse Galloping

scholarly journals Maximum Obtainable Energy Harvesting Power from Galloping-Based Piezoelectrics

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mohammad Yaghoub Abdollahzadeh Jamalabadi ◽  
Mostafa Safdari Shadloo ◽  
Arash Karimipour
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
Bluff Body ◽  
Mechanical Energy ◽  
Average Power ◽  
Electrical Energy ◽  
Load Resistance ◽  
Nonlinear Motion ◽  
Rc Circuit ◽  
Deflection Limit

In this paper, the maximum obtainable energy from a galloping cantilever beam is found. The system consists of a bluff body in front of wind which was mounted on a cantilever beam and supported by piezoelectric sheets. Wind energy caused the transverse vibration of the beam and the mechanical energy of vibration is transferred to electrical charge by use of piezoelectric transducer. The nonlinear motion of the Euler–Bernoulli beam and conservation of electrical energy is modeled by lumped ordinary differential equations. The wind forces on the bluff body are modeled by quasisteady aeroelasticity approximation where the fluid and solid corresponding dynamics are disconnected in time scales. The linearized motion of beam is limited by its yield stress which causes to find a limit on energy harvesting of the system. The theory founded is used to check the validity of previous results of researchers for the effect of wind speed, tip cross-section geometry, and electrical load resistance on onset speed to galloping, tip displacement, and harvested power. Finally, maximum obtainable average power in a standard RC circuit as a function of deflection limit and synchronized charge extraction is obtained.

Harvesting Vibration From Rotating Machinery as a Power Source for a Wireless Sensor Node

2009 ◽  
Author(s):  
H. Salleh ◽  
N. M. Rashid ◽  
K. A. Wahib
Keyword(s):  
Integrated Circuit ◽  
Power Output ◽  
Sensor Node ◽  
Energy Harvester ◽  
Electrical Energy ◽  
Rotating Machinery ◽  
Wireless Sensor ◽  
Design Parameters ◽  
Wireless Sensor Node ◽  
In Series

The wireless sensor device which uses battery can cause problems when the wireless nodes are large in number and when the nodes are placed in the difficult area to access. Therefore, it is advantageous for the sensor node to be capable of extracting energy from the environment, making it self-powered, self-sustaining and lowering overall cost of the wireless network. Improvement in integrated circuit (IC) technology has made the overall power consumption of circuit very small which leads to a very promising application of the vibration-based energy harvester micro power generator (VEHM). This paper discusses on some practical design considerations in harvesting vibration from rotating machinery to power up a wireless sensor node. It also focuses on the effect of shape of the VEHM on its power output. These parameters are actually important as part of the key design parameters in harvesting the vibration from ambient. The energy harvester is made of piezoelectric bimorph bender materials poling in series to transform ambient vibrations into electrical energy. The power output for the VEHM made of single and multiple array of PZT bimorph bender are investigated and the effect of triangular and the rectangular PZT bimorph bender are compared. Two sets of VEHM device have been tested to work in the range of 50 Hz–110 Hz to power up a wireless sensor node for condition monitoring application. The experimental results are presented and compared to the previous similar work. It is found that the triangular shape bender generates more power compared to rectangular form whether it is single or multiple connected in series. Testing results proved that triangular VEHM of the same volume and fundamental frequency when compared to rectangular VEHM can improve the overall power generated by the generator.

Complex Impedance Matching for Power Improvement of a Circular Piezoelectric Energy Harvester

2011 ◽  
Vol 148-149 ◽  
pp. 169-172 ◽  
Author(s):  
Hong Yan Wang ◽  
Xiao Biao Shan ◽  
Tao Xie
Keyword(s):  
Output Power ◽  
Power Output ◽  
Energy Harvester ◽  
Impedance Matching ◽  
Maximum Output Power ◽  
Complex Impedance ◽  
Complex Conjugate ◽  
Maximum Output ◽  
Piezoelectric Energy ◽  
Matching Load

The impedance matching and the optimization of power from a circular piezoelectric energy harvester with a central-attached mass are studied. A finite element model is constructed to analyze the electrical equivalent impedance of the circular piezoelectric energy harvester. Furthermore, the complex conjugate matching load is used to extract the maximum output power of the energy harvester. The power output from complex conjugate matching load is compared with the power output from the resistive matching load and a constant resistance, separately. The results suggest that the complex conjugate matching can result in a significant increase of the output power for all frequencies. The effective bandwidth of the piezoelectric energy harvester is extended significantly.

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