Energy harvesting from underwater base excitation of a piezoelectric composite beam

Abstract

In this paper, we investigate energy harvesting from underwater base excitation of a piezoelectric composite beam. Four different geometric configurations are experimentally studied in which the beam is either fully submerged or is partially immersed, with an eighth, a quarter, or a half of its length vibrating underwater. The frequency and the amplitude of base excitation are systematically varied along with the shunting resistance to investigate the principles of piezoelectric energy harvesting from underwater vibrations. Results demonstrate that increasing the wet length produces a consistent reduction of the resonance frequency and the quality factor of underwater vibrations. On the other hand, the harvested power is found to generally decrease as the submersion length is increased. Experimental results are interpreted through a distributed piezohydroelastic model that accounts for added mass and nonlinear hydrodynamic damping effects. A reduced order modal model is further established to parametrically explore the system response across a variety of geometrical and physical parameters.

Hydrodynamic Thrust Generation and Power Consumption Investigations for Piezoelectric Fins With Different Aspect Ratios

“…2. It should be noted that, the inertia coefficient is estimated close to unity when the linear hydrodynamic forces are dominant on the predictions of classical flow solutions of the two-dimensional fluidstructure problem [19], whereas recent experimental and analytical data presented by Cha et al [32] and Shahab and Erturk [24,25] show that the inertia coefficient is controlled by the aspect ratio, especially for ψ < 5.…”

“…The electromechanical coupling term, ϑ, and capacitance, C p , are obtained using the mixing rules formulation [34]. Furthermore, Γ(x, t) is the hydrodynamic load per unit length due to the surrounding fluid (and L is the overall overhang length) and is expressed using Morison's semi-empirical equation as [9,26,27,32]:…”

“…In the present paper, an experimentally validated nonlinear electrohydroelastic model for underwater resonant actuation of piezoelectric MFC cantilevers in quiescent water is developed based on the Euler-Bernoulli theory while incorporating the fluid effects using Morison's semi-empirical model [26,27] as in Kopman and Porfiri [9] and Cha et al [32]. The inertia and drag coefficients in Morison's equation are experimentally identified by applying low input voltages for linear underwater actuation tests (resulting in both small deformations and small electric fields) [32,33]. Based on experimental data for the underwater vibration of passive aluminum plates and MFCs with different aspect ratios [33], a quadratic polynomial quotient curve fit is given for the dimensionless inertia coefficient.…”

Energy harvesting from a piezoelectric biomimetic fish tail

“…While most of these studies have focused on in-air applications, a few recent efforts have considered the possibility of underwater energy harvesting through piezoelectric materials [30,31,32,33,34,35]. For example, the so-called energy harvesting eel converting energy from a fluid flow has been demonstrated in [30,31].…”

“…For example, the so-called energy harvesting eel converting energy from a fluid flow has been demonstrated in [30,31]. Energy harvesting from underwater base excitation of piezoelectric beams has been investigated in [32,35]. Finally, hydraulic pressure fluctuations as a source of usable energy for piezoelectric harvesting have been studied in [33,34].…”