Fluttering energy harvesters in the wind: A review

Abstract

The growing area of harvesting energy by aerodynamically-induced flutter in a fluid stream is reviewed. Numerous approaches were found to understand, demonstrate and [sometimes] optimise harvester performance based on Movement-Induced or Extraneously-Induced Excitation. Almost all research was conducted in smooth, unidirectional flow domains; either experimental or computational. The power outputs were found to be very low when compared to conventional wind turbines, but potential advantages could be lower noise levels. A consideration of the likely outdoor environment for fluttering harvesters revealed the flow would be highly turbulent and having a mean flow angle in the horizontal plane that could approach a harvester from any direction. Whilst some multiple harvester systems in smooth, well-aligned flow found enhanced efficiency (due to beneficial wake interaction) this would require an invariant flow approach angle. It was concluded that further work needs to be performed to find a universally accepted metric for efficiency and to understand the effects of the realities of the outdoors, including the highly variable and turbulent flow conditions likely to be experienced.

FLEHAP: A Wind Powered Supply for Autonomous Sensor Nodes

“…The experimental results show that the efficiency of this system in centimeter-dimensions-scale is competitive with respect other traditional technologies (e.g., C = 20 cm, S = 70 cm, A spanned = 50 cm 2 , η > 8%, Re = 4500), such as microturbines [21] and fluttering devices of comparable dimensions on the market [14].…”

“…After the seminal work of McKinney and DeLaurier [8], in recent years many devices adopting this effect have been proposed: Bryant et al [9], Zhu et al [10], Fei et al [11], Abdelkefi et al [12], Nabavi and Zhang [13], and McCharty et al [14].…”

“…The state of art of such energy-harvester devices claims self-sustained excitation motions at low wind speed (from 3 to 5 m/s) characterized by a modest power density when an electrical extraction strategy is adopted [12,14]. This is due to the low amount of mechanical energy, Ew, available in these working conditions: Ew = 0.5 × ρ × As × U 2 , where ρ is the density of the air, U is the wind speed, and As is the spanned area surface, i.e., the area covered by the harvester in its periodic motion.…”

Review of vibration-based energy harvesting technology: Mechanism and architectural approach

“…102 Figure 26 illustrates the simulated outputs of using single and multiple layers of aeroelastics VEH. 105 103 Sirohi and Mahadik 34 have demonstrated an analytical PE EH mode-the vibration or oscillation of the prismatic VEH occurs because of aerodynamic galloping by wind movement, as represented in Figure 27.…”

Coupling Motion and Energy Harvesting of Two Side-by-Side Flexible Plates in a 3D Uniform Flow

“…Recently, the robotic models of fish swimming have been of great interest in ocean engineering, and a wide diversity of approaches have been taken for the mechanical design of fish-inspired systems [9][10][11], such as a carangiform fish robot [12,13] and a batoid-inspired robot [14][15][16]. Besides the active flow control mechanisms used in bionic propulsion, passive flapping or vibrating dynamics have also been applied in developing renewable energy harvesters, which are usually based on compliant materials, such as elastic-mounted cylinders and piezoelectric membranes [17][18][19]. Although these interaction phenomena are common, they still puzzle researchers due to their complicated dynamics.…”