عنوان مقاله [English]
In this study, energy harvesting by porous beams exposed to external fluid flow is studied analytically. The nonlinear electromechanical non-linear differential equations governing the transverse vibration of porous beams under external fluid flow have been extracted using Euler-Bernoulli beam theory and Hamilton's principle. A cantilever bimorph beam with a concentrated mass at its end, which is equipped with piezoelectric layer, is considered as an energy harvesting system. After solving the nonlinear equations of motion, the effect of different parameters on the amount of harvested energy is examined. The results show that in the areas of the lock-in phenomenon, the amount of harvested energy by the beam has its maximum value. Also, the porosity distribution has significant effect on the maximum amplitude of oscillations, as well as the energy harvested by the porous beam. The lock-in phenomenon for the porous beam with distribution of symmetrical porosity (wall stiffness), asymmetric porosity distribution and uniform porosity distribution is taken around u=0.15. In addition, for electrical resistance R = 100kΩ, the maximum voltage generated for the bimorph porous beam by the distribution of symmetrical porosity in the wall stiffness, asymmetric porosity distribution and uniform porosity distribution is 0.39V, 0.44V and 0.57V, respectively.