Optimal electromagnetic energy extraction from transverse galloping

Abstract

A fully coupled electro-fluid-elastic model for electromagnetic energy harvesting from Transverse Galloping is presented here. The model considers a one degree-of-freedom galloping oscillator where fluid forces are described resorting to quasi-steady conditions; the electromagnetic generator is modelled by an equivalent electrical circuit where power is dissipated at an electrical load resistance; the galloping oscillator and the electromagnetic model are coupled appropriately. Two different levels of simplification have been made depending on the comparison between the characteristic electrical and mechanical timescales. The effect of the electrical resistance load on the energy harvested is studied theoretically. For fixed geometry and mechanical parameters, it has been found that there exists an optimal electrical resistance load for each reduced velocity. On the practical side, this result can be helpful to design tracking-point strategies to maximize energy harvesting for variable flow velocity conditions.

Enhanced mechanical energy extraction from transverse galloping using a dual mass system

“…In operation the system would work as follows: under the action of the fluid flow, the galloping body oscillates perpendicular to the direction of the flow and drives the secondary mass (or dual mass). This secondary mass then drives the permanent magnet of a linear electromagnetic generator (note that for simplicity, the electromagnetic generator has been considered as a linear damper in the mathematical model, see [35]). Relative motion between the magnet and the coil of the generator produces electrical current.…”

Energy harvesting by means of flow-induced vibrations on aerospace vehicles

“…The electromagnetic generator can be modelled by an equivalent electrical circuit where power is dissipated at an electrical load resistance [73]. The modelling can be generalized when there are multiple magnets and coils, such as the energy harvester in [74] that consisted of three magnets in which one magnet floated between two fixed magnets.…”

Theoretical study of the energy harvesting of a cantilever with attached prism under aeroelastic galloping

“…Then, oscillatory motion (transverse to the flow) develops with increasing amplitude until the energy dissipated per cycle by mechanical damping balances the energy input per cycle from the flow (for a detailed introduction to TG the reader is referred to Parkinson [2], or Paidoussis et al [3]). If the geometry of the body and the elastic properties are appropriate, the TG instability may appear at low flow velocities and with large excitation amplitudes, making TG a very promising way to harvest energy successfully [1,4,5].…”