The role of third windows on human sound transmission of forward and reverse stimulations: A lumped-parameter approach

2020 ◽  
Vol 147 (3) ◽  
pp. 1478-1490 ◽  
Author(s):  
Lin Xue ◽  
Houguang Liu ◽  
Wenbo Wang ◽  
Jianhua Yang ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Sound Transmission ◽  
Lumped Parameter ◽  
Parameter Approach

scholarly journals Evaluation of passive autocatalytic recombiners operation efficiency by means of the lumped parameter approach

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 339-345 ◽  
Author(s):  
Tomasz Bury
Keyword(s):  
Hydrogen Generation ◽  
Cooling System ◽  
Component Mixture ◽  
Pressurized Water ◽  
Water Reactor ◽  
Safety Issues ◽  
Loss Of Coolant Accident ◽  
Lumped Parameter ◽  
Core Cooling ◽  
Parameter Approach

Abstract The problem of hydrogen behavior in containment buildings of nuclear reactors belongs to thermal-hydraulic area. Taking into account the size of systems under consideration and, first of all, safety issues, such type of analyses cannot be done by means of full-scale experiments. Therefore, mathematical modeling and numerical simulations are widely used for these purposes. A lumped parameter approach based code HEPCAL has been elaborated in the Institute of Thermal Technology of the Silesian University of Technology for simulations of pressurized water reactor containment transient response. The VVER-440/213 and European pressurised water reactor (EPR) reactors containments are the subjects of analysis within the framework of this paper. Simulations have been realized for the loss-of-coolant accident scenarios with emergency core cooling system failure. These scenarios include core overheating and hydrogen generation. Passive autocatalytic recombiners installed for removal of hydrogen has been taken into account. The operational efficiency of the hydrogen removal system has been evaluated by comparing with an actual hydrogen concentration and flammability limit. This limit has been determined for the three-component mixture of air, steam and hydrogen. Some problems related to the lumped parameter approach application have been also identified.

scholarly journals The Role of Studs in the Sound Transmission of Double Walls

2009 ◽  
Vol 95 (3) ◽  
pp. 555-567 ◽  
Author(s):  
J. Poblet-Puig ◽  
A. Rodríguez-Ferran ◽  
C. Guigou-Carter ◽  
M. Villot
Keyword(s):  
Sound Transmission

Efficiency of the lumped parameter concept and the role of liquid properties in modelling microdroplet evaporation

Fuel ◽  
2016 ◽  
Vol 166 ◽  
pp. 86-95 ◽  
Author(s):  
Dung Nguyen ◽  
Julio Soria ◽  
Damon Honnery
Keyword(s):  
Lumped Parameter

Stirling Thermocompressor: Lumped Parameter Modeling and Experimental Impact of Displacer Motion Profile on Work Output

2019 ◽  
Author(s):  
Seth Thomas ◽  
Eric J. Barth
Keyword(s):  
Experimental Validation ◽  
Model Parameters ◽  
Work Output ◽  
System Dynamics Model ◽  
Dynamics Model ◽  
Lumped Parameter ◽  
Stirling Engines ◽  
Simplified Modeling ◽  
Parameter Approach ◽  
Motion Profile

Abstract The thermocompressor, a little-known class of Stirling devices that efficiently compresses gas, presents new challenges for modeling and experimental validation. In modeling, traditional analytic assumptions about displacer motion are limiting. In experimental verification, few devices have actually been built and tested. In this paper, the authors test the feasibility of a lumped-parameter approach for predicting the performance of Stirling thermocompressors subject to different displacer motion profiles. Since the displacer of a thermocompressor can be controlled independently, unlike kinematic Stirling engines or dynamic Stirling engines, and has a large influence on output power and efficiency of the device, it is crucial that this is well captured by a system dynamics model for control. Key model parameters are simulated and results are experimentally verified on one of the few, if only, experimental thermocompressor platforms in the world. Conclusions are drawn regarding simplified modeling of the regenerator’s effectiveness and the effects on device work output by varying the displacer piston’s motion profile using different waveforms.

Vibration Dissipation Characteristics of Symmetrical Piezoelectric Networks With Passive Branches

2012 ◽  
Author(s):  
Yu Fan ◽  
Lin Li
Keyword(s):  
Dynamic Models ◽  
Vibration Suppression ◽  
Vibration Reduction ◽  
Design Guidelines ◽  
Connection Form ◽  
Network Connection ◽  
Lumped Parameter ◽  
The Given ◽  
Parameter Approach ◽  
Better Than

In this paper, a new vibration reduction approach by means of symmetric piezoelectric network is proposed, combining energy harvesting and vibration reduction. The system could be constructed by several individual structures with identical mechanical parameters, such as blades of rotor machinery. Two basic forms of network-connection are studied, in which dissipation of both mechanical and electric field is considered. Dynamic models are established by the Lumped Parameter approach and Kirchhoff’s Circuit Theorem, and the normalizing process is used to make the models more general. Subsequently, the modal information and harmonic response of piezoelectric networks with an arbitrary number of components are obtained. Based on the dynamic characteristics of piezoelectric networks, the mechanism of vibration-suppression behavior of such systems is studied. Design guidelines of these vibration reduction systems are established via parameter studies. Eventually, the optimized parameters of each network-connection form are obtained analytically. It is shown that the symmetric piezoelectric network can suppress the response of the given frequency to zero, and also perform better than pure passive piezoelectric shunts in resonant frequency band.

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