A hybrid piezoelectric–electromagnetic nonlinear vibration energy harvester excited by fluid flow

Energy harvesting mechanisms can be used to extract energy from ambient surroundings to power small electronic devices, which has a significant advantage in realizing self-sustaining wireless devices. The proposed design of this study uses the internal fluid flow within a pipe and takes advantage of the fluid– structure interaction through flow-induced vibration of a bluff body. The hybrid harvester uses the vibration to convert electrical energy through a piezoelectric material and an electromagnetic oscillator that can be tuned to resonate at the oscillation frequency. A numerical solver was used to estimate harvestable voltage for this submerged hybrid energy harvester model by using ordinary differential equations. A computational study was used to optimize the performance of the bluffbodies under the influence of the vortices for circular, triangular, ellipse, and quadrilateral shapes. Wake development was seen in the circular and triangular shapes with the ellipse having the lowest turbulence kinetic energy among the shapes. Structural deflection of the beam under resonance was compared for the different shapes, which displayed better results for triangular and elliptical bluff bodies.