Microwatt energy harvesting by exploiting flow-induced vibration

Abstract

The green technology approaches by harvesting energy from aerodynamic flowinduced vibrations using a flexible square cylinder is experimentally investigated. The practicability of flow-induced vibration system to supply a sufficient base excitation vibration in microwatt scale is evaluated through a series of wind tunnel tests with different velocities. Test are performed for high Reynolds number 3.9 × 103≤ Re 1.4 × 104 and damping ratio ζ = 0.0052. The experiment setup is able to replicate the pattern of vibration amplitude for isolated square cylinder with previous available study. Then, the experimental setup is used to study the effect of vibration cylinder in harvesting the fluid energy. A prototype of electromagnetic energy harvesting is invented and fabricated to test its performance in the wind tunnel test. Test results reveal that the harnessed power is corresponding to vibration amplitude flow pattern, but the power obtained is much lower than the vibration amplitude due to the power dissipation at the resistor. The best condition for harnessing power is identified at UR = 7.7 where the Karman Vortex-Induced Vibration (KVIV) is the largest.