Flow energy piezoelectric bimorph nozzle harvester

Abstract

There is a need for a long-life power generation scheme that could be used downhole in an oil well to produce 1 Watt average power. There are a variety of existing or proposed energy harvesting schemes that could be used in this environment but each of these has its own limitations. The vibrating piezoelectric structure is in principle capable of operating for very long lifetimes (decades) thereby possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. In order to determine the feasibility of using piezoelectrics to produce suitable flow energy harvesting, we surveyed experimentally a variety of nozzle configurations that could be used to excite a vibrating piezoelectric structure in such a way as to enable conversion of flow energy into useful amounts of electrical power. These included reed structures, spring mass-structures, drag and lift bluff bodies and a variety of nozzles with varying flow profiles. Although not an exhaustive survey we identified a spline nozzle/piezoelectric bimorph system that experimentally produced up to 3.4 mW per bimorph. This paper will discuss these results and present our initial analyses of the device using dimensional analysis and constitutive electromechanical modeling. The analysis suggests that an order-of-magnitude improvement in power generation from the current design is possible.

Modeling and simulation of a fluttering cantilever in channel flow

“…The geometry illustrated in figure 1a and dimensional parameters in table 1 are inspired by the flow energy harvester configurations in (Sherrit et al, 2014(Sherrit et al, , 2015. We consider the beam displacement as the output of a system defined by a characteristic velocity (or flow rate), geometrical parameters, and material properties, for a total of 10 possible nondimensional groups that determine its dynamics.…”

“…Applications include wind instruments (Sommerfeldt & Strong, 1988;Backus, 1963), human snoring (Balint & Lucey, 2005;Tetlow & Lucey, 2009), vocalization (Tian et al, 2014), and enhanced heat transfer (Shoele & Mittal, 2016;Hidalgo et al, 2015). Recently, this geometry has also been used for flow-energy harvesting, with devices specifically targeting power generation for remote sensor networks (Sherrit et al, 2014(Sherrit et al, , 2015Lee et al, 2015Lee et al, , 2016. For most of these applications, the flutter instability boundary is the essential result sought, as the functional requirements of engineering designs (i.e.…”

Fluid flow nozzle energy harvesters

“…The actuator experiments chosen for the initial processing consisted of vibration almost entirely in their fundamental mode. Hence, only the = 1 solution to equation (2) is considered for the cases shown. At each frame, the x-y edge data is least squares fitted to equation 1, yielding a constant coefficient for ( ), where index is the frame number.…”

“…In this paper we are investigating using fluid flow to induce vibrations in piezoelectric transducers to generate electricity. A variety of energy harvesting systems have been developed using piezoelectric or electrostrictive materials and many distinct vibration modes have been used to generate electrical power [1,2]. The energy harvesting application we are targeting is in downhole oil/water flow with the potential for the ambient pressures to reach 30,000 psi and a temperature up to 200 o C. The necessity for energy harvesting in downhole oil producing wells is crucial, as transmitting power from the surface is complicated by difficulty of making electrical connections across production packers down inside the well.…”

Design and experimental evaluation of flextensional-cantilever based piezoelectric transducers for flow energy harvesting

“…Aeroelastic flutter, in particular, has been shown as an effective fluid-structure coupling mechanism when bimorph-type actuators have relatively low resonant frequencies (less than 300 Hz). Yet a major drawback is their brittle nature when exposed to large deformation, resulting in short lifetimes [5,6].…”