Piezoelectric Energy Harvesting Using a Porous Beam Under Fluid-Induced Vibrations

In this paper, the energy harvesting by porous beams exposed to the external fluid flow is studied. The electromechanical nonlinear differential equations of the transverse vibration behavior of porous beams exposed to external fluid flow are derived using the Euler-Bernoulli beam theory. A porous beam with concentrated mass which is equipped with a piezoelectric layer at its upper surface is considered energy harvesting. After numerically solving the governing nonlinear equations, the effect of different parameters on the generated energy is investigated. The results show that in the lock-in area, the maximum amount of energy is taken. Also, the porosity distribution has a significant effect on the maximum amplitude of the oscillations as well as the energy harvesting by the porous beam. In addition, for electrical resistance of 1000 kΩ, the maximum voltage generated for the beam with symmetrical porosity distribution in the form of wall stiffness, asymmetric porosity distribution, and uniform porosity distribution is equal to 0.39 V, 0.44 V, and 57 V, respectively, which indicates the highest energy harvesting capability of the beam with the porosity distribution of the third type.