2020/05/15 by Sankalp Tiwari, Tiwari, Sankalp, C. P. Vyasarayani +3
Engineering · #Acoustic Wave Phenomena Research #Applied Physics (physics.app-ph) #FOS: Physical sciences #Innovative Energy Harvesting Technologies #Vibration Control and Rheological Fluids
paper · pdf · doi:10.48550/arxiv.2005.07447
openalex publication_date 2020/05/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the theoretical maximum extractable average power from an energy\nharvesting device attached to a vibrating table which provides a unidirectional\ndisplacement A\sin(\ω t). The total mass of moving components in the\ndevice is m. The device is assembled in a container of dimension L,\nlimiting the displacements and deformations of components within. The masses in\nthe device may be interconnected in arbitrary ways. The maximum extractable\naverage power is bounded by \(mLA\ω3)/(\π), for motions in 1, 2, or\n3 dimensions; with both rectilinear and rotary motions as special cases; and\nwith either single or multiple degrees of freedom. The limiting displacement\nprofile of the moving masses for extracting maximum power is discontinuous, and\nnot physically realizable. But smooth approximations can be nearly as good:\nwith 15 terms in a Fourier approximation, the upper limit is 99 % of the\ntheoretical maximum. Purely sinusoidal solutions are limited to \(\π)/(4)\ntimes the theoretical maximum. For both single-degree-of-freedom linear\nresonant devices and nonresonant whirling devices where the energy extraction\nmimics a linear torsional damper, the maximum average power output is\n\(mLA\ω3)/(4). Thirty-six experimental energy harvesting devices in\nthe literature are found to extract power amounts ranging from 0.0036 % to\n29 % of the theoretical maximum. Of these thirty-six, twenty achieve less\nthan 2 % and three achieve more than 20 %. We suggest, as a figure of merit,\nthat energy extraction above \(0.2 mLA\ω3)/(\π) may be considered\nexcellent, and extraction above \(0.3 mLA\ω3)/(\π) may be considered\nchallenging.\n