The thermal contact problem in nano- and micro-scale photothermal measurements

This paper presents a study on the thermoelastic contact between a wavy surface and a flat surface in the presence of a heat-conducting interstitial medium in interface gaps. The influence of applied mechanical and thermal loads on the deformation of the gaps is taken into account. The contact problem is reduced to a system of singular integro-differential equations for a temperature jump across the gaps and the height of the gaps. Solutions are obtained for the cases of thermoinsulated and heat-conducting gaps. It is shown that, in contrast to the thermoinsulated gap model, the use of the heat-conducting gap model makes it possible to construct a physically correct solution of the contact problem. It is revealed that the wavy interface with heat-conducting gaps exhibits thermal rectification. The effects of the medium’s thermal conductivity, the pressure and heat flow magnitudes and the waviness amplitude on the effective thermal contact resistance and the level of thermal rectification are analysed.

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Finite Element Modeling of Multi-Scale Thermal Contact Resistance

ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer, Parts A and B ◽

10.1115/mnht2008-52385 ◽

2008 ◽

Cited By ~ 10

Author(s):

M. K. Thompson

Keyword(s):

Finite Element ◽

Contact Resistance ◽

Thermal Contact Resistance ◽

Unit Area ◽

Thermal Contact ◽

Contact Model ◽

Micro Scale ◽

Multi Scale ◽

Macro Scale ◽

Scale Surface

Many traditional macro scale finite element models of thermal contact systems have incorporated the effect of micro scale surface topography by applying a constant value of thermal contact conductance (TCC) per unit area to the regions in contact. However, it has been very difficult to determine an appropriate TCC value for a given system and analysts typically had to rely on experimental data or values from the literature. This work presents a method for predicting micro scale TCC per unit area by incorporating micro scale surface roughness in a multi-scale iterative thermal/structural finite element contact model. The resulting TCC value is then used in a macro scale thermal/structural contact model with apparent surface form to predict the thermal contact resistance and overall thermal resistance for a commercial power electronics module.

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Influence of Thermal Contact Resistance on Frictionally Excited Thermoelastic Instability (TEI)

ASME/STLE 2004 International Joint Tribology Conference, Parts A and B ◽

10.1115/trib2004-64367 ◽

2004 ◽

Cited By ~ 1

Author(s):

J. R. Barber ◽

M. Ciavarella ◽

L. Afferante

Keyword(s):

Steady State ◽

Contact Problem ◽

Contact Resistance ◽

Thermal Contact Resistance ◽

Frictional Heating ◽

Thermal Contact ◽

Contact Problems ◽

General Stability ◽

Static Contact ◽

Steady State Solutions

Thermoelastic contact problems can posess non-unique and/or unstable steady-state solutions if there is frictional heating or if there is a pressure-dependent thermal contact resistance at the interface. These two effects have been extensively studied in isolation, but their possible interaction has not been investigated until recently. We shall discuss some idealized geometries in which the two effects are seen to form limiting cases of a more general stability and existence behavior. In most cases, frictional heating has a destabilizing effect relative to the static contact problem, but if the thermal contact resistance is very sensitive to pressure, cases of stabilization can be obtained. Also, the critical sliding speed depends on the contact pressure in contrast to results obtained in the absence of thermal contact resistance.

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