Numerical and experimental investigation of piezoelectric energy harvester based on flag-flutter

In the present era, the demand for self-powered electronic instruments is increasing and their energy consumption is decreasing. The ability to extract energy from the operating environment is of great importance in advanced industrial applications particularly in the field of aerospace. In this research, a flag-flutter based piezoelectric (PZT) energy harvester is modeled based on fluid-structure interaction (FSI) that represents an important area of research for the development of innovative energy harvesting solution. The possibility to harvest energy from Limit Cycle Oscillations (LCOs) by means of piezoelectric transduction is investigated via numerical and experimental tests. Moreover, the flutter instability of a cantilevered flag with piezoelectric (PZT) and Aluminium (Al) patches, subjected to an axial flow has been investigated. The numerical simulations are performed in MSC Nastran software and the experimental campaign is performed in a subsonic wind-tunnel. The practical interest of this instability mechanism, which can lead to self-sustained oscillations, is the possible application in flow energy harvesting. Furthermore, the critical velocities for different length of flags are also predicted numerically and experimentally. The numerical results are in good agreement with experiments, as well as with results in the literature. The maximum power output obtained by the designed harvester experimentally is found to be 1.12 $mW$ for 66.6 $kOmega$ resistance. The presented model is suitable to harvest energy and to drive wireless sensors.