Energy Harvesting with Piezoelectric Grass for Autonomous Self-Sustaining Sensor Networks.

Piezoelectric Grass;Energy Harvesting;Dual Cantilever Flutter;Flow-induced Vibration;Distributed Parameter Electromechanical Modeling;Remote Autonomous Self-sustaining Sensor Networks;Aerospace Engineering;Materials Science and Engineering;Mechanical Engineering;Science (General);Engineering;Science;Aerospace Engineering

Hobeck, Jared DaleGoulbourne, Nakhiah C. ;

University of Michigan

关键词: Piezoelectric Grass;    Energy Harvesting;    Dual Cantilever Flutter;    Flow-induced Vibration;    Distributed Parameter Electromechanical Modeling;    Remote Autonomous Self-sustaining Sensor Networks;    Aerospace Engineering;    Materials Science and Engineering;    Mechanical Engineering;    Science (General);    Engineering;    Science;    Aerospace Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/107068/jdhobeck_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The primary objective of this research is to develop a deploy-and-forget energy harvesting device for use in low velocity, highly turbulent, and unpredictable fluid flow environments. The work presented in this dissertation focuses on a novel, lightweight, highly robust, energy harvester design referred to as piezoelectric grass. This biologically inspired design consists of an array of cantilevers, constructed with piezoelectric material. When exposed to a wide range of flow conditions, these cantilevers experience vigorous persistent vibration.Included in this work is an experimentally validated theoretical analysis of the piezoelectric grass harvester generalized for the case of a single cantilever in turbulent cross-flow. A brief parameter optimization study is presented using this distributed parameter model. Two high-sensitivity pressure probes were needed to perform spatiotemporal measurements within various turbulent flows. Measurements with these probes are used to develop a turbulent fluid forcing function. This function is then combined with an analytical structural dynamics model such that not only the modal RMS displacements, but also the modal displacement power spectral density trends are predicted for a given structure. Pressure probe design, turbulence measurement techniques, and both statistical and analytical models are validated with experimental results.An experimental investigation on the energy harvesting potential of large harvester arrays containing up to 112 flexible piezoelectric structures is presented. Experimental results show that a given array will experience large amplitude, waving, resonant-type vibration over a large range of velocities, and is unaffected by large-scale turbulence upstream of the array. These dynamic characteristics make large arrays of flexible piezoelectric structures ideal for many energy harvesting applications.Lastly, this dissertation presents the first documented investigation of a flow-induced vibration phenomenon referred to as dual cantilever flutter (DCF). At a particular combination of flow velocity and distance between two adjacent beams, aeroelastic coupling between the beams causes them to become unstable and undergo limit cycle oscillations. An attractive feature of DCF for energy harvesting is that it provides robust flow-induced excitation over a large range of flow velocities. An experimentally validated lumped parameter model for DCF is presented. Results include CFD simulations that were setup and executed using ANSYS-CFX.