Nonlinear Dynamics and Design of Aeroelastic Energy Harvesters

2015 ◽  
pp. 341-379
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Wireless Sensors ◽  
Performance Enhancement ◽  
Circular Cylinders ◽  
Medical Implants ◽  
Energy Harvesters ◽  
Vortex Induced Vibrations ◽  
Flow Induced Vibrations ◽  
Self Powered ◽  
And Performance

The concept of harvesting energy from flow-induced vibrations has received a great deal of attention in the last few years. This technology would help in the replacement of small batteries that require expensive and time consuming maintenance and development of self-powered electronic devices, such as health monitoring sensors, medical implants, data transmitters, wireless sensors, and cameras. In this chapter, a particular focus is paid to the concept of harvesting energy from aeroelastic instabilities, such as flutter in airfoil sections, vortex-induced vibrations in circular cylinders, and galloping in prismatic structures. Nonlinear electroaeroelastic models for these energy harvesters are derived and validated with experimental measurements. It is shown how linear and nonlinear analyses can be used to breach traditional barriers in the design and performance enhancement of these aeroelastic energy harvesters, characterization of their behaviors, and identification of the contribution of different types of nonlinearities.

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2018 ◽  
pp. 826-862
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

scholarly journals Nonlinear dynamics and performance enhancement of asymmetric potential bistable energy harvesters

2018 ◽  
Vol 94 (2) ◽  
pp. 1183-1194 ◽  
Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Chris R. Bowen ◽  
Ying Zhang ◽  
Jing Lin
Keyword(s):  
Nonlinear Dynamics ◽  
Performance Enhancement ◽  
Energy Harvesters ◽  
And Performance

Modeling and Performance Enhancement of Low-Frequency Energy Harvesters

2015 ◽  
pp. 159-196 ◽  
Author(s):  
Abdessattar Abdelkefi
Keyword(s):  
Performance Enhancement ◽  
Mechanical Energy ◽  
Excitation Frequency ◽  
Low Frequency ◽  
Ocean Waves ◽  
Sensors And Actuators ◽  
Low Frequencies ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
And Performance

There exist numerous low-frequency excitation sources, such as walking, breathing, and ocean waves, capable of providing viable amounts of mechanical energy to power many critical devices, including pacemakers, cell phones, MEMS devices, wireless sensors, and actuators. Harvesting significant energy levels from such sources can only be achieved through the design of devices capable of performing effective energy transfer mechanisms over low frequencies. In this chapter, two concepts of efficient low-frequency piezoelectric energy harvesters are presented, namely, variable-shaped piezoelectric energy harvesters and piezomagnetoelastic energy harvesters. Linear and nonlinear electromechanical models are developed and validated in this chapter. The results show that the quadratic shape can yield up to two times the energy harvested by a rectangular one. It is also demonstrated that depending on the available excitation frequency, an enhanced energy harvester can be tuned and optimized by changing the length of the piezoelectric material or by changing the distance between the two tip magnets.

Preparation and Characterization of Polyacrylonitrile Membranes with High Strength via Thermally Induced Phase Separation Process

2014 ◽  
Vol 789 ◽  
pp. 205-208
Author(s):  
Chun Yi Liu ◽  
Chun Ju He
Keyword(s):  
Phase Separation ◽  
Performance Enhancement ◽  
Water Flux ◽  
High Strength ◽  
Thermally Induced Phase Separation ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Structure Modulation ◽  
And Performance

Polyacrylonitrile (PAN) membranes were prepared via thermally induced phase separation (TIPS) process using polyethylene glycol (PEG) as plasticizing agent and polyvinyl pyrrolidone (PVP) as porogen, which presented high strength, i.e. 6MPa. A systematic study was carried out to investigate the effect of PVP content, PAN concentration and cooling conditions on the pore shape, pore size, water flux and mechanical properties of the membranes, which were characterized by scanning electron microscope, filtration measurement and tensile test. PAN membranes with uniformly distributed pores were fabricated by adjusting the mixed diluent composition. Results of filtration confirm that water flux of PAN membranes mainly depends on the pore structure. Moreover, while PVP content is increased, water flux first increases and then declines, and tensile strength and elongation at break first declines and then increases. In conclusion, the successful application of TIPS provides a new route to the structure modulation and performance enhancement of PAN membranes.

Electrical energy generation by squeezing graphene-based aerogel in an electrolyte

Nanoscale ◽  
2021 ◽  
Author(s):  
Xiaoshuang Zhou ◽  
Xin Chen ◽  
Hao Zhu ◽  
Xu Dong ◽  
lvzhou Li ◽  
...  
Keyword(s):  
Wave Energy ◽  
Wireless Sensors ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Power Supplies ◽  
Energy Harvesters ◽  
Portable Power ◽  
Ocean Wave Energy ◽  
Self Powered ◽  
Electrical Energy Generation

Mechanical energy harvesters are widely studied because of their diverse applications, such as harvesting of ocean wave energy, self-powered wireless sensors, portable power supplies and so on. To be feasible,...

scholarly journals Continuous Sliding Mode Control of Flow-Induced Vibrations

1995 ◽  
Vol 2 (5) ◽  
pp. 365-372 ◽  
Author(s):  
A. Baz
Keyword(s):  
Sliding Mode ◽  
Flexible Structures ◽  
Theoretical Models ◽  
Circular Cylinders ◽  
Design Parameters ◽  
Flow Conditions ◽  
Parameter Uncertainties ◽  
Vortex Induced Vibrations ◽  
Flow Induced Vibrations ◽  
Structural Uncertainties

Vortex-induced vibrations of flexible circular cylinders and galloping oscillations of square prisms are controlled using a robust continuous sliding mode (CSM) controller. The ability of the CSM controller in rejecting the flow-induced disturbances and accommodating parameter uncertainties is numerically demonstrated. In the present study, emphasis is placed on the development of theoretical models that describe the interaction between the flexible structures, the flow-induced excitation, and the CSM controller. In our development, the vortex-induced vibrations are based on the lift-oscillator model of Hartlen and Currie and the galloping phenomenon is described using Parkinson and Smith's model. The effectiveness of the CSM controller in suppressing the flow-induced vibrations of cylinders and square prisms is evaluated at various flow conditions and levels of structural uncertainties. The effect of the design parameters of the CSM controller on its performance is also investigated. The results obtained in the study suggest the potential of the robust control strategy presented as an important tool for rejecting undesirable and unmeasurable disturbances acting on critical structures that have considerably large parameter uncertainties.

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