Towards energy harvesting through flow-induced snap-through oscillations

Abstract

Recently, energy harvesting through periodic snapping, namely snap-through, has gained significant attention for energy harvesting applications. In this study, the snapping dynamics of a buckled sheet with two ends clamped were numerically investigated to explore its energy harvesting characteristics in a Poiseuille channel flow. It is found that the elastic sheet comes into either a static equilibrium or snap-through oscillation state. The oscillation state can be initiated more readily by buckling the sheet to a length ratio in the vicinity of ΔL*=0.3 and/or by raising the Reynolds number. Additionally, the effects of three governing parameters, including the length ratio, the bending stiffness of the sheet, and the Reynolds number, on the energy harvesting characteristics were also examined for the oscillation cases. The finding shows that, in a post-equilibrium state, increasing the length ratio and bending stiffness could enhance the total energy for harvesting, primarily by raising the elastic potential energy. The most effective portion for energy collection always lies in the aft half of the sheet. Moreover, transitions from an equilibrium state to a snap-through oscillation state increase both the elastic potential and kinetic energies. Our numerical results gain deeper insights into the dynamics of a pre-compressed elastic sheet and its interaction with a laminar channel flow. The results may provide some guidance on optimizing relevant energy harvesting systems.