In the present study, the performance of a cylinder-based piezoelectric wind energy harvester attached to an elastic beam is numerically simulated. The wind ow perpendicular to the beam axis causes an oscillatory aerodynamic force exerted on the beam tip. The beam and the piezoelectric layer are modeled as elastic continuous bodies, and the continuum governing equations of the solid and piezoelectric layers are extracted. Moreover, the induced lift force by the vortex shedding downstream of the cylinder is estimated by the modi ed van der Pol wake oscillator equation. The cantilever mode shapes and the Galerkin method are applied to solve the three transient and coupled equations of elastic de ection, electrical resistance, and uid force. Besides verifying the accuracy of the modi ed van der Pol equation, a moving object Computational Fluid Dynamics (CFD) simulation is also conducted. The e ects of oscillator length, cylinder diameter, resistance load, structure and piezoelectric thickness as well as the wind speed on the produced power are investigated. According to the obtained results, upon increasing the cylinder diameter from 0.05 m by 100, 200, and 300%, the output power is increased by 219, 801, and 1502% at a wind speed of 5 m/s.