Small Wind Energy Harvesting From Galloping Using Piezoelectric Materials (original) (raw)
Related papers
Harvesting Wind Energy Using a Galloping Piezoelectric Beam
Journal of Vibration and Acoustics, 2011
Galloping of structures such as transmission lines and bridges is a classical aeroelastic instability that has been considered as harmful and destructive. However, there exists potential to harness useful energy from this phenomenon. This paper focuses on harvesting wind energy that is being transferred to a galloping beam. The beam has a rigid tip body with a D-shaped cross section. Piezoelectric sheets are bonded on the top and bottom surface of the beam. During galloping, vibrational motion is input to the system due to aerodynamic forces on the D-section, which is converted into electrical energy by the piezoelectric (PZT) sheets. The relative importance of various parameters of the system such as wind speed, material properties of the beam, electrical load and beam’s natural frequency are discussed. Experimental and analytical investigations of dynamic response and power output are performed on a representative device. A maximum output power of 1.14 mW was measured at a wind ve...
Journal of Intelligent Material Systems and Structures, 2014
The concept of harvesting energy from galloping oscillations of a bluff body with different cross-section geometries attached to a cantilever beam is investigated. To convert these oscillations into electrical power, a piezoelectric transducer is attached to the transverse degree of freedom of the prismatic structure. Modal analysis is performed to determine the exact mode shapes of the structure. A coupled nonlinear distributed-parameter model is developed to determine the effects of the cross-section geometry, load resistance, and wind speed on the level of the harvester power. The quasi-steady approximation is used to model the aerodynamic loads. Linear analysis is performed to investigate the effects of the electrical load resistance and the cross-section geometry on the onset speed of galloping. The results show that the electrical load resistance and the cross-section geometry affect significantly the onset speed of galloping. Nonlinear analysis is performed to determine the effects of the electrical load resistance, cross-section geometry, and wind speed on the system's outputs and particularly the level of the harvested power. A comparison of the performance of the different cross sections in terms of displacement and harvested power is presented. The results show that different sections are better for harvesting energy over different regions of the flow speed. The results also show that maximum levels of harvested power are accompanied with minimum transverse displacement amplitudes for all considered (square, D, and triangular) cross-section geometries.
2018
Due to a large oscillation amplitude, galloping can be an admissible scenario to actuate the piezoelectric-based energy harvester. In the case of harvesting energy from galloping vibrations, a prismatic bluff body is attached on the free end of a piezoelectric cantilever beam and the oscillation occurs in a plane normal to the incoming flow. The electrical power then can be extracted from the piezoelectric sheet bonded in the cantilever structure due to the dynamic strain. This study is proposed to develop a theoretical model of a galloping-based piezoelectric energy harvester. A FEM procedure is utilized to determine dynamic characteristics of the structure. Whereas the aerodynamic lift and drag coefficients of the tip bluff body are determined using CDF. The results show that the present method gives precise results of the power generated by harvester. It was found that D-section yields the greatest galloping behavior and hence the maximum power.
This paper develops an experimentally validated model of a piezoelectric energy harvester under combined aeroelasticgalloping and base excitations. To that end, an energy harvester consisting of a thin piezoelectric cantilever beam subjected to vibratory base excitation is considered. To permit galloping excitation, a bluff body is rigidly attached at the free end such that a net aerodynamic lift is generated as the incoming airflow separates on both sides of the body giving rise to limit cycle oscillations when the flow velocity exceeds a critical value. A nonlinear electromechanical distributed-parameter model of the harvester under the combined excitation is derived using the energy approach and by adopting the nonlinear Euler-Bernoulli beam theory, linear constitutive relations for the piezoelectric transduction, and the quasi-steady assumption for the aerodynamic loading. The partial differential equations of the system are discretized and a reduced-order-model is obtained. The mathematical model is validated by conducting a series of experiments with different loading conditions represented by wind speed, base excitation amplitude, and excitation frequency around the primary resonance.
Performance of piezoelectric energy harvester with various ratio substrate and micro windmill
TELKOMNIKA Telecommunication Computing Electronics and Control, 2024
One of the mechanical energy harvesters, piezoelectric energy harvesters (PEHs), produces electricity in response to an external load, which leads to stress and strain in the cantilever beam. The study focused on performance PEH due to collisions between micro windmill blades and PEH substrate. The substrate has dimensions of 10 cm × 6 cm × 1 mm in length, width, and thickness, respectively. Experimental setup was in wind tunnel with a crosssection of 250 mm × 250 mm and blower to generated wind flow inside the tunnel. The wind speeds were set up at 6, 7, and 8 m/s, and then three ratios, namely 1:1, 1:2, and 1:3, were analyzed in output voltage and the deflection. The performance of energy harvesting in a ratio of 1:1 and wind speed of 8 m/s produces a deflection of 2.05 cm, the highest voltage of 12.67 volts, and an effective voltage of 5.62 volts. It was found that ratio 1:1 has a greater mass weight and cross-section than others, leading to more curvature in the PEH beam when the collision occurs. Besides that, the high speed of the micro windmill rotation causes collisions between the blades and PEH to become more frequent.
Temperature impact on the performance of galloping-based piezoaeroelastic energy harvesters
Smart Materials and Structures, 2013
The effects of ambient temperature on the level of harvesting energy from galloping oscillations of a bluff body are investigated. A nonlinear-distributed-parameter model is developed to determine variations in the onset speed of galloping and the level of the harvested power when the ambient temperature is varied. The considered harvester consists of a bimorph piezoelectric cantilever beam with a prismatic-structure tip mass. A modal analysis is performed to derive the exact mode shapes and natural frequencies of the beam-structure system and their dependence on temperature variations. The quasi-steady representation is used to model the aerodynamic loads. The linear analysis shows that the temperature and the electrical load resistance affect the onset speed of galloping significantly. The nonlinear analysis shows that temperature variation affects the level of the harvested power.
Theor. Appl. Mech. Lett., 2014
In this paper, we investigate experimentally the concept of energy harvesting from galloping oscillations with a focus on wake and turbulence effects. The harvester is composed of a unimorph piezoelectric cantilever beam with a square cross-section tip mass. In one case, the harvester is placed in the wake of another galloping harvester with the objective of determining the wake effects on the response of the harvester. In the second case, meshes were placed upstream of the harvester with the objective of investigating the effects of upstream turbulence on the response of the harvester. The results show that both wake effects and upstream turbulence significantly affect the response of the harvester. Depending on the spacing between the two squares and the opening size of the mesh, wake and upstream turbulence can positively enhance the level of the harvested power.
Modeling and nonlinear analysis of piezoelectric energy harvesting from transverse galloping
Smart Materials and Structures, 2013
A model for harvesting energy from galloping oscillations of a bar with an equilateral triangle cross-section attached to two cantilever beams is presented. The energy is harvested by attaching piezoelectric sheets to cantilever beams holding the bar. The derived nonlinear distributed-parameter model is validated with previous experimental results. The quasi-steady approximation is used to model the aerodynamic loads. The power levels that can be generated from these vibrations, and the variations of these levels with the load resistance and wind speed, are determined. Linear analysis is performed to validate the onset of galloping speed with experimental measurements. The effects of the electrical load resistance on the onset of galloping are then investigated. The results show that the electrical load resistance affects the onset speed of galloping. A nonlinear analysis is also performed to determine the effects of the electrical load resistance and the nonlinear torsional spring on the level of the harvested power. The results show that maximum levels of harvested power are accompanied by minimum transverse displacement amplitudes. It is also demonstrated that there is an optimum load resistance that maximizes the level of the harvested power.
Piezo-aeroelastic energy harvesters convert airflow induced vibrations into electrical energy, while the availability and affordability of piezoelectric transducers offer a class of flapping foil energy harvesters mostly in micro-to milliwatts scale which need to be tuned to match the characteristic frequencies. The present work presents a brief review of aeroelastic instability of a generic typical wing section due to the free stream flow field which is utilized as an oscillating foil energy converter. For propaedeutic analysis a generic piezo-aeroelastic cantilevered beam is defined and treated as a typical section. The basic governing equation of this generic structure is treated as a three degrees of freedom electro-dynamic system, with the first two-degree-of freedom comprising the standard binary aeroelastic system with additional relevant terms to represent the influence of a piezoelectric embedded element on the cantilevered wing. Following the philosophical approach of binary aeroelastic system, the problem is mathematically formulated and solved for the range of solutions that can be obtained depending on the prevailing physical properties of the system, focusing on the stability characteristics of the generic system. The characteristic of the unsteady aerodynamics of the oscillating system associated with favorable energy harvesting capabilities are assessed.