scholarly journals The effect of non-uniform damping on flutter in axial flow and energy-harvesting strategies

2012 ◽  
Vol 468 (2147) ◽  
pp. 3620-3635 ◽  
Author(s):  
Kiran Singh ◽  
Sébastien Michelin ◽  
Emmanuel De Langre
Keyword(s):  
Theoretical Model ◽  
Energy Harvesting ◽  
Axial Flow ◽  
Flexible Structure ◽  
Fluid Loading ◽  
Power Harvesting ◽  
Reduced Order ◽  
Slender Structure ◽  
Preliminary Study ◽  
System Energy

The problem of energy harvesting from flutter instabilities in flexible slender structures in axial flows is considered. In a recent study, we used a reduced-order theoretical model of such a system to demonstrate the feasibility for harvesting energy from these structures. Following this preliminary study, we now consider a continuous fluid-structure system. Energy harvesting is modelled as strain-based damping, and the slender structure under investigation lies in a moderate fluid loading range, for which the flexible structure may be destabilized by damping. The key goal of this work is to analyse the effect of damping distribution and intensity on the amount of energy harvested by the system. The numerical results indeed suggest that non-uniform damping distributions may significantly improve the power-harvesting capacity of the system. For low-damping levels, clustered dampers at the position of peak curvature are shown to be optimal. Conversely for higher damping, harvesters distributed over the whole structure are more effective.

scholarly journals Flow Energy Harvesting With Piezoelectric Flags

2014 ◽  
Author(s):  
Olivier Doaré ◽  
Sébastien Michelin ◽  
Miguel Pineirua ◽  
Yifan Xia
Keyword(s):  
Theoretical Model ◽  
Energy Harvesting ◽  
Parametric Study ◽  
Axial Flow ◽  
Continuous Model ◽  
Flow Energy ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
Lock In ◽  
Good Agreement

In this article, energy harvesting with a fluttering cantilevered plate covered by piezoelectric patches in an axial flow is adressed. A theoretical model is presented which is then discretized and numerically integrated to perform a parametric study of the energy harvesting efficiency of the system. When one, two or three piezoelectric patches cover the plate, the optimal distributions of the patches that maximize the efficiency are obtained. Experimental results are presented, which are in good agreement with the model. When a significantly high number of patches of small size are considered, a continuous model is used to study the influence of a resonant harvesting circuit. A lock-in phenomenon is evidenced, which is able to significantly increase the efficiency.

Geometric Optimization of a Piezoelectric Power Harvesting Plate for Increased Bandwidth

2007 ◽  
Author(s):  
Lee Wells ◽  
Yirong Lin ◽  
Henry Sodano ◽  
Byeng Youn
Keyword(s):  
Energy Harvesting ◽  
Electrical Energy ◽  
Maximum Energy ◽  
Geometric Optimization ◽  
Signal Frequency ◽  
Field Energy ◽  
Energy Scavenging ◽  
Power Harvesting ◽  
Topology And Shape Optimization ◽  
Battery Technology

The continual advances in wireless technology and low power electronics have allowed the deployment of small remote sensor networks. However, current portable and wireless devices must be designed to include electrochemical batteries as the power source. The use of batteries can be troublesome due to their limited lifespan, thus necessitating their periodic replacement. Furthermore, the growth of battery technology has remained relatively stagnant over the past decade while the performance of computing systems has grown steadily, which leads to increased power usage from the electronics. In the case of wireless sensors that are to be placed in remote locations, the sensor must be easily accessible or of disposable nature to allow the device to function over extended periods of time. For this reason the primary question becomes how to provide power to each node. This issue has spawned the rapid growth of the energy harvesting field. Energy scavenging devices are designed to capture the ambient energy surrounding the electronics and convert it into usable electrical energy. The concept of power harvesting works towards developing self-powered devices that do not require replaceable power supplies. However, when designing a vibration based energy harvesting system the maximum energy generation occurs when the resonant frequency of the system is tuned to the input. This poses certain issues for their practical application because structural systems rarely vibrate at a signal frequency. Therefore, this effort will investigate the optimal geometric design of two dimensional energy harvesting systems for maximized bandwidth. Topology and shape optimization will be used to identify the optimal geometry and experiments will be performed to characterize the energy harvesting improvement when subjected to random vibrations.

Decentralized Control of a Tower Crane

1999 ◽  
Author(s):  
Kiyoshi Takagi ◽  
Hidekazu Nishimura
Keyword(s):  
Decentralized Control ◽  
Three Dimensional ◽  
Reduced Order Model ◽  
Flexible Structure ◽  
Order Model ◽  
Modeling And Control ◽  
Reduced Order ◽  
Tower Crane ◽  
Three Dimensional Models ◽  
And Control

Abstract This paper deals with modeling and control of a crane mounted on a tower-like flexible structure. A fast transfer of the load causes the sway of the load rope and the vibration of the flexible structure. Our object is to control both the sway and the vibration by the inherent capability of the tower crane. This paper makes its three-dimensional models for simulation and reduced-order-model in order to design the decentralized control system. Then, we design the decentralized H∞ compensator and verify the efficiency by simulations and experiments.

Nano-Mixture Coating and Geometrical Configuration Impact on Cantilever Based Piezoelectric Energy Harvesting System

2018 ◽  
Vol 5 (3-4) ◽  
pp. 53-65 ◽  
Author(s):  
Dinesh R. Palikhel ◽  
Tyrus A. McCarty ◽  
Jagdish P. Sharma
Keyword(s):  
Energy Harvesting ◽  
Transport System ◽  
Power Output ◽  
Limiting Factor ◽  
Piezoelectric Energy Harvesting ◽  
Intermodal Transport ◽  
Power Harvesting ◽  
Piezoelectric Energy ◽  
Energy Harvesting System ◽  
The Impact

Abstract Vibrational energy from intermodal transport system can be recovered through the application of piezoelectric energy harvesting system. The intermodal vibration sources are passenger cars and freight trucks moving on streets and highways, trains moving on railway tracks and planes moving on airport runways. However, the primary limiting factor of the application of the piezoelectric energy harvesting system has been the insignificant power output for power storage or to directly power electrical device. A special nano-mixture coating is developed to enhance the energy harvesting capability of the conventional piezoelectric material. This research investigates the impact of the nano-mixture coating on the power output. The experimental results of the nano-mixture coated system show substantial and explicit improvement on the power output. Alternative geometrical designs, trapezoidal and triangular are explored in anticipation for improved power output. But the rectangular energy harvester demonstrates better power harvesting capability. The results presented in this paper show the potential of the nano-mixture coating in power harvesting from intermodal transport system.

Theoretical Model of the Spanwise Mixing Caused by Periodic Incoming Wakes

1994 ◽  
Author(s):  
K. Imanari
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Turbulent Diffusion ◽  
Axial Flow ◽  
Single Stage ◽  
Mixing Coefficients ◽  
Predicted Values ◽  
Good Agreement ◽  
Axial Flow Compressors

A theoretical model is proposed for the spanwise mixing caused by periodic incoming wakes in the context of turbulent diffusion in axial-flow compressors prior to repeating-stage conditions. The model was used to predict the spanwise mixing coefficients across a stator of a single-stage compressor without IGVs. The correctness of the theory was demonstrated by the results that the predicted values were in good agreement with the associated experimental data.

Preliminary study on development of PVDF nanofiber based energy harvesting device for an artery microrobot

2011 ◽  
Vol 88 (8) ◽  
pp. 2251-2254 ◽  
Author(s):  
Weiting Liu ◽  
Xiaoying Cheng ◽  
Xin Fu ◽  
Cesare Stefanini ◽  
Paolo Dario
Keyword(s):  
Energy Harvesting ◽  
Preliminary Study
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