Experimental and numerical studies on energy harvesting from harmonic loads acting upon the wings of high aspect ratio MAVs

In this study, a microgenerator is designed to supply the energy needed for electrical circuits of a MAV using piezoelectric materials. For this purpose, a composite airplane wing including all structural elements such as the ribs, spars and skins was designed in COMSOL multiphysics software. On the spar of this wing, a piezoelectric piece is modeled. The wing is modeled as a cantilever beam that its end is excited in an oscillatory manner with given frequencies and amplitudes. During the oscillation, the stress and strain of the wing elements are obtained using the finite element method and the amount of the generated voltage is calculated by coupling the piezoelectric governing equations with the strains. Next, an experimental model is created with the same characteristics of the numerical model and tested. The results of the numerical solution are compared with the results of the experimental tests for the verification. Afterwards, the effects of parameters such as the aspect ratio, the size of piezoelectric materials and the spar thickness on the generated voltage are studied. Finally, the results have been discussed.