scholarly journals Constructive Aerodynamic Interference in a Network of Weakly Coupled Flutter-Based Energy Harvesters

Aerospace ◽  
2020 ◽  
Vol 7 (12) ◽  
pp. 167
Author(s):  
Emmanuel Beltramo ◽  
Martín E. Pérez Segura ◽  
Bruno A. Roccia ◽  
Marcelo F. Valdez ◽  
Marcos L. Verstraete ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Performance ◽  
High Energy ◽  
Physical Parameters ◽  
Flexible Wings ◽  
Energy Harvesters ◽  
Weakly Coupled ◽  
Sufficient Power ◽  
Extended Operation ◽  
Cantilevered Beams

Converting flow-induced vibrations into electricity for low-power generation has received growing attention over the past few years. Aeroelastic phenomena, good candidates to yield high energy performance in renewable wind energy harvesting (EH) systems, can play a pivotal role in providing sufficient power for extended operation with little or no battery replacement. In this paper, a numerical model and a co-simulation approach have been developed to study a new EH device for power generation. We investigate the problem focusing on a weakly aerodynamically coupled flutter-based EH system. It consists of two flexible wings anchored by cantilevered beams with attached piezoelectric layers, undergoing nonlinear coupled bending–torsion limit cycle oscillations. Besides the development of individual EH devices, further issues are posed when considering multiple objects for realizing a network of devices and magnifying the extracted power due to nonlinear synergies and constructive interferences. This work investigates the effect of various external conditions and physical parameters on the performance of the piezoaeroelastic array of devices. From the viewpoint of applications, we are most concerned about whether an EH can generate sufficient power under a variable excitation. The results of this study can be used for the design and integration of low-energy wind generation technologies into buildings, bridges, and built-in sensor networks in aircraft structures.

scholarly journals Multicriteria Decision Analysis of Material Selection of High Energy Performance Residential Building

2013 ◽  
Vol 8 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Monika Čuláková ◽  
Silvia Vilčeková ◽  
Jana Katunská ◽  
Eva Krídlová Burdová
Keyword(s):  
Decision Analysis ◽  
Building Materials ◽  
Material Selection ◽  
Slovak Republic ◽  
Energy Performance ◽  
High Energy ◽  
Physical Parameters ◽  
Zero Energy ◽  
Wood Panel ◽  
Alternative Scenarios

Abstract In world with limited amount of energy sources and with serious environmental pollution, interest in comparing the environmental embodied impacts of buildings using different structure systems and alternative building materials will be increased. This paper shows the significance of life cycle energy and carbon perspective and the material selection in reducing energy consumption and emissions production in the built environment. The study evaluates embodied environmental impacts of nearly zero energy residential structures. The environmental assessment uses framework of LCA within boundary: cradle to gate. Designed alternative scenarios of material compositions are also assessed in terms of energy effectiveness through selected thermal-physical parameters. This study uses multi-criteria decision analysis for making clearer selection between alternative scenarios. The results of MCDA show that alternative E from materials on nature plant base (wood, straw bales, massive wood panel) present possible way to sustainable perspective of nearly zero energy houses in Slovak republic

scholarly journals Thermal Dynamic Behavior in Bi-Zone Habitable Cell with and without Phase Change Materials

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 41
Author(s):  
Hanae El Fakiri ◽  
Lahoucine Ouhsaine ◽  
Abdelmajid El Bouardi
Keyword(s):  
Thermal Behavior ◽  
Thermal Comfort ◽  
Phase Change ◽  
Dynamic Behavior ◽  
Phase Change Materials ◽  
Energy Performance ◽  
High Energy ◽  
Water Heater ◽  
Simplified Modeling

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.

Analysis of physical parameters associated with the measurement of high-energy x-ray penumbra

1984 ◽  
Vol 11 (4) ◽  
pp. 491-497 ◽  
Author(s):  
D. J. Dawson ◽  
J. M. Harper ◽  
A. C. Akinradewo
Keyword(s):  
High Energy ◽  
Physical Parameters ◽  
X Ray

Ultrasonic Creep Damage Detection by Frequency Analysis for Boiler Piping

2006 ◽  
Vol 129 (4) ◽  
pp. 713-718 ◽  
Author(s):  
Hiroaki Hatanaka ◽  
Nobukazu Ido ◽  
Takuya Ito ◽  
Ryota Uemichi ◽  
Minoru Tagami ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Damage Detection ◽  
Fossil Fuel ◽  
Creep Damage ◽  
High Energy ◽  
Assessment Method ◽  
Nondestructive Method ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

Boiler piping of fossil-fuel combustion power generation plants are exposed to high-temperature and high-pressure environments, and failure of high-energy piping due to creep damage has been a concern. Therefore, a precise creep damage assessment method is needed. This paper proposes a nondestructive method for creep damage detection of piping in fossil-fuel combustion power generation plants by ultrasonic testing. Ultrasonic signals are transformed to signals in a frequency domain by Fourier transform, and a specific frequency band is chosen. To determine the creep damage, the spectrum intensities are calculated. Calculated intensities have a good correlation to life consumption of the weld joints, and this method is able to predict the remaining life of high-temperature piping, which has been already installed.

Nonlinear Stochastic Feedback Controllers for Vibratory Energy Harvesters With Power Flow Constraints

2011 ◽  
Author(s):  
Ian L. Cassidy ◽  
Jeffrey T. Scruggs ◽  
Sam Behrens
Keyword(s):  
Power Generation ◽  
Power Flow ◽  
Flow Direction ◽  
Average Power ◽  
Control Input ◽  
Stochastic Disturbances ◽  
Feedback Controllers ◽  
Energy Harvesters ◽  
System States ◽  
Feedback Laws

This study addresses the formulation of feedback controllers for stochastically-excited vibratory energy harvesters. Maximizing power generation from stochastic disturbances can be accomplished using LQG control theory, with the transducer current treated as the control input. For the case where the power flow direction is unconstrained, an electronic drive capable of extracting as well as delivering power to the transducer is required to implement the optimal controller. It is demonstrated that for stochastic disturbances characterized by second-order, bandpass-filtered white noise, energy harvesters can be passively tuned such that optimal stationary power generation only requires half of the system states for feedback in the active circuit. However, there are many applications where the implementation of a bi-directional power electronic drive is infeasible, due to the higher parasitic losses they must sustain. If the electronics are designed to be capable of only single-directional power flow (i.e., where the electronics are incapable of power injection), then these parasitics can be reduced significantly, which makes single-directional converters more appropriate at smaller power scales. The constraint on the directionality of power flow imposes a constraint on the feedback laws that can be implemented with such converters. In this paper, we present a sub-optimal nonlinear control design technique for this class of problems, which exhibits an analytically computable upper bound on average power generation.

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