This work aims to study a novel configuration of a flow-induced piezoelectric vibration-based energy harvesting structure. In this system, the resonant frequency of the energy harvesting structure is adjusted by placing additional patches at the bottom part of the beam structure. This is aimed to maximize the power output when the natural frequency of the structure approaches the vortex shedding frequency. The computational model of the flow-induced vortex shedding frequency is based both on the Strouhal theory and Kelvin-Helmholtz instability theory and the results are verified using the finite element modeling by Fluent and experimental investigation. The excitation frequency is varied from 0 to 0.85 Hz by changing the flow velocity from 0 to 0.325 m/s, while the natural frequency of the energy harvesting structure is varied from 5.7 to 1.2Hz by increasing the thickness of additional patches from 0 to 10 mm. The effectiveness of this fluid-induced vibration energy harvesting structure is demonstrated in this work.