Characterizing Macroscopic Thermal Resistance Across Contacting Interfaces Through Local Understanding of Thermal Transport

MRS Advances ◽  
2018 ◽  
Vol 3 (44) ◽  
pp. 2735-2741
Author(s):  
Seshu Nimmala ◽  
S. Aria Hosseini ◽  
Jackson Harter ◽  
Todd Palmer ◽  
Eric Lenz ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Ballistic Transport ◽  
Industrial Applications ◽  
Boundary Resistance ◽  
Boltzmann Transport ◽  
Lateral Transport ◽  
Intimate Contact ◽  
Access Resistance ◽  
Dynamics Simulations ◽  
Thermal Resistors

ABSTRACTThermal resistance across the interface between touching surfaces is critical for many industrial applications. We developed a network model to predict the macroscopic thermal resistance of mechanically contacting surfaces. Contacting interfaces are fractally rough, with small islands of locally intimate contact separated by regions with a wider gas filled boundary gap. Heat flow across the interface is therefore heterogeneous and thus the contact model is based on a network of thermal resistors representing boundary resistance at local contacts and the access resistance for lateral transport to contacts. Molecular dynamics simulations have been performed to characterize boundary resistance of Silicon Alumina interfaces for testing the sensitivity of thermal resistance to contact opening. Boltzmann transport simulations of access resistance in Si are conducted in the ballistic transport regime.

Molecular Dynamics Prediction of the Thermal Resistance of Solid-Solid Interfaces in Superlattices

2006 ◽  
Author(s):  
A. J. H. McGaughey ◽  
J. Li
Keyword(s):  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Ballistic Transport ◽  
System Size ◽  
Phonon Transport ◽  
Kubo Formula ◽  
Jones Potential ◽  
Lennard Jones ◽  
Interface Thermal Resistance ◽  
Dynamics Simulations

Molecular dynamics simulations are used to predict the thermal resistance of solid-solid interfaces in crystalline superlattices using a new Green-Kubo formula. The materials on both sides of the interfaces studied are modeled with the Lennard-Jones potential and are only differentiated by their masses. To obtain the interface thermal resistance, a correlation length in the bulk materials is first predicted, which approaches a system-size independent value for larger systems. The interface thermal resistance is found to initially increase as the layer length is increased, and then to decrease as the phonon transport shifts from a regime dominated by ballistic transport to one dominated by diffusive transport.

Multiscale Simulations of Thermoelectric Properties of PBTE

2008 ◽  
Author(s):  
Bo Qiu ◽  
Hua Bao ◽  
Xiulin Ruan
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Thermoelectric Properties ◽  
Transport Coefficients ◽  
Multiscale Simulation ◽  
Full Potential ◽  
Boltzmann Transport ◽  
Pair Potentials ◽  
Dynamics Simulations

In this paper, thermoelectric properties of bulk PbTe are calculated using first principles calculations and molecular dynamics simulations. The Full Potential Linearized Augmented Plane Wave (FP-LAPW) method is first employed to calculate the PbTe band structure. The transport coefficients (Seebeck coefficient, electrical conductivity, and electron thermal conductivity) are then computed using Boltzmann transport equation (BTE) under the constant relaxation time approximation. Interatomic pair potentials in the Buckingham form are also derived using ab initio effective charges and total energy data. The effective interatomic pair potentials give excellent results on equilibrium lattice parameters and elastic constants for PbTe. The lattice thermal conductivity of PbTe is then calculated using molecular dynamics simulations with the Green-Kubo method. In the end, the figure of merit of PbTe is computed revealing the thermoelectric capability of this material, and the multiscale simulation approach is shown to have the potential to identify novel thermoelectric materials.

Negative differential thermal resistance induced by ballistic transport

2009 ◽  
Vol 79 (5) ◽  
Author(s):  
Wei-Rong Zhong ◽  
Ping Yang ◽  
Bao-Quan Ai ◽  
Zhi-Gang Shao ◽  
Bambi Hu
Keyword(s):  
Thermal Resistance ◽  
Ballistic Transport

Molecular Dynamics Simulations of Interfacial Heat and Mass Transfer at Nanostructured Surface

2007 ◽  
Author(s):  
Gyoko Nagayama ◽  
Masako Kawagoe ◽  
Takaharu Tsuruta
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Boundary Condition ◽  
Thermal Resistance ◽  
Hydrodynamic Resistance ◽  
Hydrophilic Surface ◽  
Dynamics Simulations ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Continuum

The nanoscale heat and mass transport phenomena play important roles on the applications of nanotechnologies with great attention to its differences from the continuum mechanics. In this paper, the breakdown of the continuum assumption for nanoscale flows has been verified based on the molecular dynamics simulations and the heat transfer mechanism at the nanostructured solid-liquid interface in the nanochannels is studied from the microscopic point of view. Simple Lennard-Jones (LJ) fluids are simulated for thermal energy transfer in a nanochannel using nonequilibrium molecular dynamics techniques. Multi-layers of platinum atoms are utilized to simulate the solid walls with arranged nanostructures and argon atoms are employed as the LJ fluid. The results show that the interface structure (i.e. the solid-like structure formed by the adsorption layers of liquid molecules) between solid and liquid are affected by the nanostructures. It is found that the hydrodynamic resistance and thermal resistance dependents on the surface wettability and for the nanoscale heat and fluid flows, the interface resistance cannot be neglected but can be reduced by the nanostructures. For the hydrodynamic boundary condition at the solid-liquid interface, the no-slip boundary condition holds good at the super-hydrophilic surface with large hydrodynamic resistance. However, apparent slip is observed at the low hydrodynamic resistance surface when the driving force overcomes the interfacial resistance. For the thermal boundary condition, it is found that the thermal resistance at the interface depends on the interface wettability and the hydrophilic surface has lower thermal resistance than that of the hydrophobic surfaces. The interface thermal resistance decreases at the nanostructed surface and significant heat transfer enhancement has been achieved at the hydrophilic nanostructured surfaces. Although the surface with nanostrutures has larger surface area than the flat surface, the rate of heat flux increase caused by the nanostructures is remarkable.

Investigation of the Influence of Technological Factors on the Characteristics of Flexible Non-Adhesive Foil Dielectrics

2020 ◽  
Vol 25 (6) ◽  
pp. 505-516
Author(s):  
A.V. Vorobyov ◽  
◽  
V.D. Zhora ◽  
N.I. Plis ◽  
S.P. Timoshenkov ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Electrical Characteristics ◽  
Traditional Use ◽  
Total Thermal Resistance ◽  
Technological Factors ◽  
High Adhesion ◽  
Negative Effect ◽  
The Stability ◽  
Thermal Resistors ◽  
The Given

Currently, the traditional use of varnish-foil dielectrics for manufacturing resistors, resistive assemblies and heating elements has been supplemented by their application in production of thermal resistors, the membranes of acoustic and photoelectric transformers. As a rule, the non-adhesive foil dielectrics sustain the affect of high temperatures, permit to significantly increase the density of elements and have better quality characteristics, because the adhesives have negative effect upon the electrical characteristics of the materials, manufactured with their application. Also, the adhesives have comparatively low thermal resistance, which manifests on the total thermal resistance of foil dielectric and the items manufactured on it, especially in case when as a base polyimide is used. In the paper the flexible foil dielectrics for electronic equipment and their manufacturing technology have been considered. The advantages of the non-adhesive foil dielectrics with complete imidization of the polymer base have been shown. The technology of manufacturing the varnish-foil dielectrics, used in manufacturing highly reliable microcircuits of modification 2 and of highly technological membranes of acoustic transformers, has been developed. The polyimide base of the dielectrics has high adhesion to foil and the guaranteed uniformity of the imidization extent 95-100 %. This provides the stability of technological conditions in the process of manufacturing the items from the given materials, as well as an increase of the storage life of the varnish-foil dielectrics up to 12 months.

Thermal conductivity and interfacial Thermal Resistance Behavior for the Polyaniline (C3N)– boron carbide (BC3) Heterostructure

2021 ◽  
Author(s):  
Arian Mayelifartash ◽  
Mohammad Ali Abdol ◽  
Sadegh Sadeghzadeh
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Boron Carbide ◽  
Molecular Dynamics Simulations ◽  
Thermal Conductance ◽  
Interfacial Thermal Resistance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Non Equilibrium

In this paper, by employing non-equilibrium molecular dynamics simulations (NEMD), the thermal conductance of hybrid formed by polyaniline (C3N) and boron carbide (BC3) in both armchair and zigzag configurations has...

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