scholarly journals Measurement of Line Distribution of Thermal Contact Resistance Using Microscopic Lock-In Thermography

2021 ◽  
Vol 8 (1) ◽  
pp. 18
Author(s):  
Takuya Ishizaki ◽  
Ai Ueno ◽  
Hosei Nagano
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Resistance Measurement ◽  
Phase Lag ◽  
Contact Interface ◽  
Geometrical Condition ◽  
Infrared Microscope ◽  
The One ◽  
Lock In

This paper proposes a new thermal contact resistance measurement method using lock-in thermography. Using the lock-in thermography with an infrared microscope, the local temperature behavior in the frequency domain across the contact interface was visualized in microscale. Additionally, a new thermal contact resistance measurement principle was constructed considering the superimposition of the reflected and transmitted temperature wave at the boundary and taking into account the intensity distribution of the heating laser as the gaussian distribution, and the specific geometrical condition of the laminated plate sample. As a result of the experiments, the one-dimensional distribution of the thermal contact resistance was obtained along the contact interface from the analysis of the phase lag.

scholarly journals Dynamic Thermal Contact Resistance Measurement Method Using Lock-in Thermography

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 42 ◽  
Author(s):  
Ishizaki ◽  
Igami ◽  
Ueno ◽  
Nagano
Keyword(s):  
Contact Resistance ◽  
Measurement Method ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Side Surface ◽  
Resistance Measurement ◽  
Phase Lag ◽  
Infrared Microscope ◽  
Measurement Principle ◽  
Lock In

This paper proposes a new thermal contact resistance measurement method using lock-in thermography. By the lock-in thermography with an infrared microscope, the dynamic temperature behavior across the contact interface was visualized in the sample side surface. Meanwhile, a new thermal contact resistance measurement principle was constructed by the superimposition of the temperature wave from virtual heat sources in consideration of the thermal contact resistance at the interface. Consequently, the thermal contact resistance was obtained as a fitting parameter by fitting the theoretical curve to the measured amplitude and phase lag. The validity of the principle was shown.

Development of an Experimental Procedure for Thermal Contact Resistance Estimation at the Glass/Metal Contact Interface

2013 ◽  
Vol 6 (2) ◽  
Author(s):  
B. Abdulhay ◽  
B. Bourouga ◽  
F. Alzetto ◽  
C. Challita
Keyword(s):  
Heat Flux ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Thermal Conditions ◽  
Metal Contact ◽  
Contact Interface ◽  
Equivalent Thermal Conductivity ◽  
Experimental Procedure ◽  
Glass Metal

In this paper, an experimental device is designed and developed in order to estimate thermal conditions at the glass/metal contact interface. This device is made of two parts: The upper part contains the tool (piston) made of bronze and a heating device to raise the temperature of the piston to 700 °C. The lower part is composed of a lead crucible and a glass sample. The assembly is provided with a heating system, an induction furnace of 6 kW for heating the glass up to 950 °C. The developed experimental procedure has permitted the estimation of the thermal contact resistance (TCR) using a developed measurement principle based on the inverse technique developed by Beck et al. (1985, Inverse Heat Conduction: III Posed Problems, Wiley Inter-science, New York). The semitransparent character of the glass has been taken into account by an additional radiative heat flux and an equivalent thermal conductivity. After the set-up tests, reproducibility experiments for a specific contact pressure have been carried out. Results show a good repeatability of the registered and estimated parameters such as the piston surface temperature, heat flux density, and TCR. The estimated value of TCR reaches 2 × 10−3 K m2/W with a maximum dispersion that does not exceed 6%.

Evaluation of Thermal Contact Resistance at the Interface Composed of Dissimilar Materials

2010 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura
Keyword(s):  
Thermal Conductivity ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Empirical Equation ◽  
Thermal Contact ◽  
Dissimilar Materials ◽  
Heat Flows ◽  
Mating Surface ◽  
The Difference ◽  
The One

When jointed portions of structures and machines are subjected to thermal loads, various problems and troubles occur due to the difference in thermal expansions between mating parts. In order to accurately analyze thermal and mechanical behaviors of the joints, the effect of thermal contact resistance must be taken into account. In this paper, thermal contact coefficient, which is the reciprocal of thermal contact resistance, at the interface composed of dissimilar materials is quantitatively measured by infrared thermography. The target materials are common engineering materials such as carbon steel, stainless steel and aluminum alloy. It has been shown in the previous papers that there exits a significant directional effect in thermal contact coefficients when the mating surface is composed of different materials. That is, thermal contact coefficient has a larger value when the heat flows from the material with lower thermal conductivity to the one with higher thermal conductivity. The effects of contact pressure and surface roughness on the coefficient are also evaluated in this work. Using the measured data, an empirical equation to estimate thermal contact coefficient is proposed, for the purpose of engineering applications, which correlates closely with the experimental data.

scholarly journals Study on Thermal Contact Resistance Estimation in Planar Medium

2018 ◽  
Vol 36 (1) ◽  
pp. 28-34
Author(s):  
Jingjing Wen ◽  
Leitao Li ◽  
Chengwu Liu ◽  
Bin Wu
Keyword(s):  
Heat Transfer ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Estimation Methods ◽  
Transfer Model ◽  
Calculation Error ◽  
Contact Interface ◽  
Temperature Measuring ◽  
Planar Medium

Thermal contact resistance(TCR) is one of the important parameters in heat transfer problems of engineering, and it is necessary to estimate the value of TCR effectively in many engineering fields. Considering the limitation of current estimation methods of TCR such as only focusing on one-dimensional thermal conduction, getting a single value of TCR merely, and the temperature measuring points only being placed in temperature gradient direction of mediums, boundary element method(BEM) and conjugate gradient method are combined to estimate the TCR in planar mediums. The value of TCR in relation to the position of contact interface line is estimated with this method, and the positions of temperature measuring points can be selected randomly because of the characteristic of BEM that there is no necessity to discrete the inner area and it is sufficient to discrete the boundary. The analysis of calculation examples base on heat transfer model of planar medium demonstrates that:this method can estimate the TCR effectively, but the ill-posedness is also existed in this method which is one of the inverse problems, and the calculation error of TCR is increased with the distance from temperature measuring points to contact interface, the estimation precision and stability can be improved after optimization with least square method.

On Simple Prediction Method for Thermal Contact Resistance Between Wavy Surfaces With Thermal Interface Material Under Low Mean Nominal Contact Pressure (Fundamental Study Based on 1-D Model)

2015 ◽  
Author(s):  
Toshio Tomimura ◽  
Yasushi Koito ◽  
Taewan Do ◽  
Masaru Ishizuka ◽  
Tomoyuki Hatakeyama
Keyword(s):  
Contact Resistance ◽  
Contact Pressure ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Thermal Interface Material ◽  
Surface Model ◽  
Contact Interface ◽  
Fundamental Study ◽  
Thermal Interface ◽  
Wavy Surfaces

The thermal contact resistance (TCR) is the crucial issue in the field of heat removal from systems like electronic equipment, satellite thermal control systems, and so on. To cope with the problem, a lot of studies have been done mainly for flat rough surfaces. However, as pointed out so far, there are still wide discrepancies among measured and predicted TCRs, even for similar materials. To investigate the key factors for the abovementioned discrepancies, a fundamental analysis was conducted in our previous study [1] using a simple contact surface model, which was composed of the unit cell model proposed by Tachibana [2] and Sanokawa [3]. Furthermore, by introducing a 2-D microscopic surface model, which consists of random numbers and Abbott’s bearing area curve, the effects of surface waviness and roughness on the temperature fields near the contact interface have been investigated microscopically [4]. In this study, based on a 1-D wavy surface model, a fundamental study has been conducted to predict TCR and the thermal contact conductance (TCC), which is a reciprocal of TCR, between wavy surfaces with the thermal interface material (TIM) under a relatively low mean nominal contact pressure of 0.1–1.0 MPa. From comparison between the calculated and measured results, it has been shown that, in spite of a simple 1-D analysis, the present model predicts the temperature drop at the contact interface, which is obtained as the product of TCR and the heat rate flowing through TIM, within some 10 to 60% error for a TIM with the thermal conductivity of 2.3 W/(m·K) and the initial thickness of 0.5, 1 and 2 mm.

Thermal Contact Resistance of Anisotropic Materials

1970 ◽  
Vol 92 (1) ◽  
pp. 17-20 ◽  
Author(s):  
N. Vutz ◽  
S. W. Angrist
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Anisotropic Materials ◽  
Geometric Transformation ◽  
Contact Interface ◽  
Material Anisotropy ◽  
Transformation Technique ◽  
Factors Affecting ◽  
Material Hardness

This work presents an extension of the understanding of thermal contact resistance to include anisotropic materials. The extension involves a mathematical geometric transformation which leaves the thermal currents unchanged while making the temperature distribution in the anisotropic materials soluble by previously published methods. The development of this transformation technique is presented, and the effect of material anisotropy is calculated for a set of interface orientations and material conductivities which characterize typical contact situations. The degree of material anisotropy and the orientation of the contact interface are shown to be important factors affecting the contact resistance in addition to surface roughness, material hardness, and contact load.

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