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%.

New Mathematical Model to Estimate Tissue Blood Perfusion, Thermal Contact Resistance and Core Temperature

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Abdusalam Alkhwaji ◽  
Brian Vick ◽  
Tom Diller
Keyword(s):  
Heat Flux ◽  
Parameter Estimation ◽  
Contact Resistance ◽  
Core Temperature ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Simulated Data ◽  
Thermal Conditions ◽  
Blood Perfusion ◽  
Simple Parameter

Analytical solutions were developed based on the Green’s function method to describe heat transfer in tissue including the effects of blood perfusion. These one-dimensional transient solutions were used with a simple parameter estimation technique and experimental measurements of temperature and heat flux at the surface of simulated tissue. It was demonstrated how such surface measurements can be used during step changes in the surface thermal conditions to estimate the value of three important parameters: blood perfusion (wb), thermal contact resistance (R″), and core temperature of the tissue (Tcore). The new models were tested against finite-difference solutions of thermal events on the surface to show the validity of the analytical solution. Simulated data was used to demonstrate the response of the model in predicting optimal parameters from noisy temperature and heat flux measurements. Finally, the analytical model and simple parameter estimation routine were used with actual experimental data from perfusion in phantom tissue. The model was shown to provide a very good match with the data curves. This demonstrated the first time that all three of these important parameters (wb, R″, and Tcore) have simultaneously been estimated from a single set of thermal measurements at the surface of tissue.

Soil Heat Flux Plates: Heat Flow Distortion and Thermal Contact Resistance

2007 ◽  
Vol 99 (1) ◽  
pp. 304-310 ◽  
Author(s):  
Thomas J. Sauer ◽  
Tyson E. Ochsner ◽  
Robert Horton
Keyword(s):  
Heat Flux ◽  
Heat Flow ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Soil Heat Flux ◽  
Flow Distortion

Experimental Approach for Thermal Contact Resistance Estimation at the Glass / Metal Interface

2013 ◽  
Author(s):  
Bakri Abdulhay ◽  
Brahim Bourouga ◽  
Florent Alzetto ◽  
Ali Al Shaer ◽  
Ahmed Elmarakbi
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Experimental Approach ◽  
Thermal Contact ◽  
Metal Interface ◽  
Glass Metal

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.

Modeling and Estimating Simulated Burn Depth Using the Perfusion and Thermal Resistance Probe

2013 ◽  
Vol 7 (3) ◽  
Author(s):  
Abdusalam Al-Khwaji ◽  
Brian Vick ◽  
Tom Diller
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Parameter Estimation ◽  
Thermal Resistance ◽  
Contact Resistance ◽  
Core Temperature ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Blood Perfusion ◽  
Thermal Event

A new thermal perfusion probe operates by imposing a thermal event on the tissue surface and directly measuring the temperature and heat flux response of the tissue with a small sensor. The thermal event is created by convectively cooling the surface with a small group of impinging jets using room temperature air. The hypothesis of this research is that this sensor can be used to provide practical burn characterization of depth and severity by determining the thickness of nonperfused tissue. To demonstrate this capability the measurement system was tested with a phantom tissue that simulates the blood perfusion of tissue. Different thicknesses of plastic were used at the surface to mimic layers of dead tissue. A mathematical model developed by Alkhwaji et al. (2012, “New Mathematical Model to Estimate Tissue Blood Perfusion, Thermal Contact Resistance and Core Temperature,” ASME J. Biomech. Eng., 134, p. 081004) is used to determine the effective values of blood perfusion, core temperature, and thermal resistance from the thermal measurements. The analytical solutions of the Pennes bioheat equation using the Green's function method is coupled with an efficient parameter estimation procedure to minimize the error between measured and analytical heat flux. Seven different thicknesses of plastic were used along with three different flow rates of perfusate to simulate burned skin of the phantom perfusion system. The resulting values of thermal resistance are a combination of the plastic resistance and thermal contact resistance between the sensor and plastic surface. Even with the uncertainty of sensor placement on the surface, the complete set of thermal resistance measurements correlate well with the layer thickness. The values are also nearly independent of the flow rate of the perfusate, which shows that the parameter estimation can successfully separate these two parameters. These results with simulated burns show the value of this minimally invasive technique to measure the thickness of nonperfused layers. This will encourage further work with this method on actual tissue burns.

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.

The Effect of Thermal Contact Resistance on Heat Transfer Between Periodically Contacting Surfaces

1973 ◽  
Vol 95 (3) ◽  
pp. 411-412 ◽  
Author(s):  
J. R. Howard ◽  
A. E. Sutton
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Analog Computer ◽  
Contact Interface ◽  
Computer Study ◽  
One Dimensional

An analog-computer study is made of one-dimensional heat conduction through two bars whose axes are in line and whose adjacent ends make and break contact periodically. The work extends a previous study to take account of imperfect thermal contact at the contact interface. The effect of frequency and duration of contact are also discussed.

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