Tunability of acoustic phonon transmission and thermal conductance in three dimensional quasi-periodically stubbed waveguides

2015 ◽  
Vol 117 (11) ◽  
pp. 114308 ◽  
Author(s):  
Zhong-Xiang Xie ◽  
Jing-Zhong Liu ◽  
Xia Yu ◽  
Hai-Bin Wang ◽  
Yuan-Xiang Deng ◽  
...  
Keyword(s):  
Acoustic Phonon ◽  
Three Dimensional ◽  
Thermal Conductance

Acoustic phonon transport and ballistic thermal conductance through a three-dimensional double-bend quantum structure

2008 ◽  
Vol 104 (5) ◽  
pp. 054312 ◽  
Author(s):  
Fang Xie ◽  
Ke-Qiu Chen ◽  
Y. G. Wang ◽  
Qing Wan ◽  
B. S. Zou ◽  
...  
Keyword(s):  
Acoustic Phonon ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Phonon Transport ◽  
Quantum Structure

Effects of the Heat Transfer at the Side Walls on Natural Convection in Cavities

1990 ◽  
Vol 112 (2) ◽  
pp. 370-378 ◽  
Author(s):  
Y. Le Peutrec ◽  
G. Lauriat
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Fluid Flows ◽  
Heat Losses ◽  
Transfer Rates ◽  
Side Walls ◽  
The Difference

Numerical solutions are obtained for fluid flows and heat transfer rates for three-dimensional natural convection in rectangular enclosures. The effects of heat losses at the conducting side walls are investigated. The problem is related to the design of cavities suitable for visualizing the flow field. The computations cover Rayleigh numbers from 103 to 107 and the thermal conductance of side walls ranging from adiabatic to commonly used glazed walls. The effect of the difference between the ambient temperature and the average temperature of the two isothermal walls is discussed for both air and water-filled enclosures. The results reported in the paper allow quantitative evaluations of the effects of heat losses to the surroundings, which are important considerations in the design of a test cell.

Thermal Conductance of a Surface Phonon-Polariton Crystal Made up of Polar Nanorods

2017 ◽  
Vol 72 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Jose Ordonez-Miranda ◽  
Karl Joulain ◽  
Younes Ezzahri
Keyword(s):  
Energy Transport ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Volume Ratio ◽  
Phonon Thermal Conductivity ◽  
Propagation Length ◽  
Surface Phonon ◽  
Surface Phonon Polariton

AbstractWe demonstrate that the energy transport of surface phonon-polaritons can be large enough to be observable in a crystal made up of a three-dimensional assembly of nanorods of silicon carbide. The ultralow phonon thermal conductivity of this nanostructure along with its high surface area-to-volume ratio allows the predominance of the polariton energy over that generated by phonons. The dispersion relation, propagation length, and thermal conductance of polaritons are numerically determined as functions of the radius and temperature of the nanorods. It is shown that the thermal conductance of a crystal with nanorods at 500 K and diameter (length) of 200 nm (20 μm) is 0.55 nW·K−1, which is comparable to the quantum of thermal conductance of polar nanowires.

scholarly journals Characteristics of acoustic phonon transport and thermal conductance in multi-terminal graphene junctions

2016 ◽  
Vol 65 (8) ◽  
pp. 086301
Author(s):  
Qing Qian-Jun ◽  
Zhou Xin ◽  
Xie Fang ◽  
Chen Li-Qun ◽  
Wang Xin-Jun ◽  
...  
Keyword(s):  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport

Thermal conductance bottleneck of a three dimensional graphene–CNT hybrid structure: a molecular dynamics simulation

2020 ◽  
Vol 22 (1) ◽  
pp. 337-343 ◽  
Author(s):  
Zepei Yu ◽  
Yanhui Feng ◽  
Daili Feng ◽  
Xinxin Zhang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Thermal Transport ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Hybrid Structure ◽  
Dynamics Simulation ◽  
Atomistic Structure

We observed the atomistic structure of the junction to study mechanism governing the thermal transport across GCNT.

Acoustic phonon transport and thermal conductance in a periodically modulated quantum wire

2007 ◽  
Vol 40 (5) ◽  
pp. 1497-1500 ◽  
Author(s):  
Li-Ming Tang ◽  
Lingling Wang ◽  
Wei-Qing Huang ◽  
B S Zou ◽  
Ke-Qiu Chen
Keyword(s):  
Quantum Wire ◽  
Acoustic Phonon ◽  
Thermal Conductance ◽  
Phonon Transport

A three-dimensional fractal theory based on thermal contact conductance model of rough surfaces

2017 ◽  
Vol 232 (5) ◽  
pp. 528-539 ◽  
Author(s):  
Yongsheng Zhao ◽  
Cui Fang ◽  
Ligang Cai ◽  
Zhifeng Liu
Keyword(s):  
Rough Surfaces ◽  
Fractal Theory ◽  
Thermal Contact ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Engineering Application ◽  
Thermal Contact Conductance ◽  
Real Contact Area ◽  
Contact Conductance ◽  
Elastic Plastic

The thermal contact conductance is an important problem in the field of heat transfer. In this research, a three-dimensional fractal theory based on the thermal contact conductance model is presented. The topography of the contact surfaces was fractal featured and determined by fractal parameters. The asperities in the microscale were considered as elastic, elastic-plastic, or plastic deformations. The real contact area of the asperities could be obtained based on the Hertz contact theory. It was assumed that the rough contact surface was composed of numerous discrete and parallel microcontact cylinders. Consequently, the thermal contact conductance of the surface roughness was composed of the thermal constriction conductance of microcontacts and the air medium thermal conductance of microgaps. The thermal contact conductance of rough surfaces could be calculated by the microasperities integration. An experimental set-up with annular interface was designed to verify the presented thermal contact conductance model. Three materials were used for the thermal contact conductance analysis with different fractal dimensions D and fractal roughness parameters G. The numerical results demonstrated that the thermal contact conductance could be affected by the elastic-plastic deformation of the asperities and the gap thermal conductance should not be ignored under the lower contact load. The presented model would provide a theoretical basis for thermal transfer engineering application.

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