Energy Harvesting from Wake-Induced Vibrations of a Downstream Cylinder in Tandem Arrangement

World energy demand increases every year and energy production from conventional sources, such as fossil fuels leads to environmental degradation and global warming. To counter these adverse effects more efforts are being made to harvest clean energy from renewable energy sources. This work focuses on an energy harvester that operates on flow-induced vibrations. Any structure exposed to fluid flow may experience flow-induced vibrations and the energy from these vibrations can be harvested. This work is a numerical study where the vibrations of a downstream cylinder in the wake of an identical cylinder are studied. The upstream cylinder is held stationary whereas the downstream cylinder is allowed to vibrate in transverse direction only. The spacing ratio between the cylinders is kept fixed at 2.5, and the reduced velocity is varied from 2 to 14. The mass ratio and the damping ratio are taken as 10 and 0.01, respectively. In this analysis, the maximum vibrational amplitude was observed at lock-in condition at reduced velocity of 8, and this is where the maximum efficiency was also observed.