A Unified Microscopic and Macroscopic Thermal Contact Resistance Model

2006 ◽  
Author(s):  
Ravi Prasher ◽  
Patrick Phelan
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Mean Free Path ◽  
Characteristic Dimension ◽  
Constriction Resistance ◽  
Acoustic Mismatch ◽  
The Mean ◽  
Two Sides ◽  
Heat Carriers

There are two types of thermal contact resistance at the interface of two solids. One of them is due to the constriction of heat flow lines at the interface, commonly known as thermal contact resistance. The other type of constriction resistance is microscopic in nature. If the characteristic dimension of the constriction becomes comparable to the mean free path of the heat carriers then there is a ballistic component to the constriction resistance. For different materials on the two sides, thermal boundary resistance due to acoustic mismatch becomes important. In this paper a unified model is developed which accounts for both microscopic and macroscopic contact resistances.

Thermal Contact Resistance of a Silicon Nanowire on a Substrate

2007 ◽  
Author(s):  
Dhruv Singh ◽  
Timothy S. Fisher ◽  
Jayathi Y. Murthy
Keyword(s):  
Contact Resistance ◽  
Thermal Transport ◽  
Thermal Contact Resistance ◽  
Silicon Nanowire ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Boltzmann Transport ◽  
Constriction Resistance ◽  
The Wire ◽  
Volume Method

Increased interest in determining the thermal contact resistance encountered in various nanoscale devices derives from its role as a critical bottleneck to thermal transport at submicron scales. In the present work, the contact resistance of one such configuration — a silicon nanowire on a Si substrate — has been studied. A model based on the phonon Boltzmann transport equation (BTE) in the solid and Fourier conduction in the surrounding gas is used, in conjunction with a previously published finite volume method. This approach enables the accurate computation and examination of the relative magnitudes of constriction resistance, air thermal resistances, and the bulk resistance of the wire on transverse heat transport. The results confirm that the effective resistance is dominated by constriction resistance even for low and moderate wire acoustic thicknesses and that the constriction resistance is well represented by ballistic-limit models. In the mesoscale regime when the constriction is partially diffusive, a simple addition of diffusive and ballistic resistances is shown to work reasonably well, in agreement with previously published estimates. For higher wire acoustic thicknesses, the effects of bulk scattering in the wire cannot be ignored and a simple additive formula is inadequate. The fluid surrounding the wire can act as a complementary parallel pathway for thermal transport; however, in the high gas-phase Knudsen regime, the constriction resistance remains the controlling factor for overall thermal conductance.

A New Model for Constriction Resistance of Rough Contacts between Nominally Flat Surfaces

2011 ◽  
Vol 110-116 ◽  
pp. 977-984
Author(s):  
Jun Feng Peng ◽  
Jun Hong ◽  
Yan Zhuang
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Rough Surfaces ◽  
Thermal Contact ◽  
Radial Distance ◽  
Asperity Contact ◽  
Flat Surfaces ◽  
Constriction Resistance ◽  
Nonlinear Curve Fitting ◽  
Wide Range

Thermal contact resistance plays an important role in many domains, such as microelectronics and nuclear reactors. This paper proposes a more comprehensive model for the prediction of constriction resistance of rough contact between nominally flat surfaces in vacuum. Firstly, a 3D geometrical asperity contact model is proposed based on the analysis of the profile of actual engineering surface. In this model, the contact is not simplified as a rough surface contacting with a perfectly smooth surface, but described as two rough surfaces. Oblique contact is considered and the effects of several parameters such as the shape of the asperity, the depth of interference, and the radial distance between the centerlines of the contacting asperities are investigated. Some mathematical derivations for constriction resistance are performed, and a series of numerical simulations are also carried out, covering a wide range of values of these parameters in practice applications. A comprehensive correlation for constriction resistance as a function of these parameters is finally obtained by nonlinear curve fitting, and it is validated through some comparisons and it can be used to predict more accurately the thermal contact resistance between rough surfaces.

THERMAL CONTACT RESISTANCE MATCHING TO OPTIMIZE PERFORMANCE IN THERMOELECTRIC GENERATORS

2020 ◽  
Vol 27 (7) ◽  
pp. 617-627
Author(s):  
Yuanyuan Tian ◽  
Mengjun Zhang ◽  
Junli Wang ◽  
Anbang Liu ◽  
Huaqing Xie ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Thermoelectric Generators

High‐Temperature Skin Softening Materials Overcoming the Trade‐Off between Thermal Conductivity and Thermal Contact Resistance

Small ◽  
2021 ◽  
pp. 2102128
Author(s):  
Taehun Kim ◽  
Seongkyun Kim ◽  
Eungchul Kim ◽  
Taesung Kim ◽  
Jungwan Cho ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
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