A New Method for Measuring Thermal Contact Conductance—Experimental Technique and Results

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Simon Woodland ◽  
Andrew D. Crocombe ◽  
John W. Chew ◽  
Stephen J. Mills
Keyword(s):  
Thermal Contact ◽  
New Method ◽  
Thermal Contact Conductance ◽  
Experimental Program ◽  
Material Strength ◽  
Metal Working ◽  
Test Rig ◽  
Contact Conductance ◽  
Material Parameters ◽  
Pressure Surface

Thermal contact conductance (TCC) is used to characterize heat transfer across interfaces in contact. It is important in thermal modeling of turbomachinery components and finds many other applications in the aerospace, microelectronic, automotive and metal working industries. In this paper, a new method for measuring TCC is described and demonstrated. A test rig is formed from an instrumented split tube with in-line washers and loading applied under controlled conditions. The experimental method and data analysis are described, and the effects on thermal contact conductance of important parameters such as the contact pressure, surface roughness, temperature, thermal conductivity, and material strength are investigated. Normalization of the TCC measured in the experimental program was carried out using appropriate surface and material parameters. The results of this normalization are used to compare the normalized experimental results with various models from the literature.

A New Method for Measuring Thermal Contact Conductance: Experimental Technique and Results

2008 ◽  
Author(s):  
Simon Woodland ◽  
Andrew D. Crocombe ◽  
John W. Chew ◽  
Stephen J. Mills
Keyword(s):  
Thermal Contact ◽  
New Method ◽  
Thermal Contact Conductance ◽  
Metal Working ◽  
Loading History ◽  
Test Rig ◽  
Contact Conductance ◽  
Pressure Surface ◽  
Surface Flatness ◽  
Good Agreement

Thermal contact conductance (TCC) is used to characterise heat transfer across interfaces in contact. It is important in thermal modelling of turbomachinery components and finds many other applications in the aerospace, microelectronic, automotive and metal working industries. A new method for measuring TCC is described and demonstrated. A test rig is formed from an instrumented split tube with washers in-between and loading applied in controlled conditions. The experimental method and data analysis is described, and the effect on thermal contact conductance of parameters such as contact pressure, surface roughness, surface flatness and loading history is investigated. The results of these tests are compared to those in the available literature and good agreement of trends is found. However, the tests conducted to measure the effect of load cycling on TCC have found that the TCC continues to increase beyond 20 or so load cycles, contrary to some results in the literature.

Influence of Temperature Distribution on Tighten Force in Tie-Bolt Fastened Rotor With Considering Thermal Contact Conductance

2015 ◽  
Author(s):  
He Peng ◽  
Ning Xu ◽  
Zhansheng Liu
Keyword(s):  
Surface Roughness ◽  
Thermal Expansion ◽  
Temperature Distribution ◽  
Contact Pressure ◽  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Axial Position ◽  
Contact Conductance ◽  
Pressure Surface ◽  
Axial Temperature

Tighten force has much influence on tie-bolt fastened rotor dynamics. Temperature distribution in tie-bolt fastened rotor results in thermal expansion of rotor and rods. The difference of thermal expansion between rotor and rods causes the variation of bolt load. With considering the thermal contact conductance, the thermal model of tie-bolt fastened rotor was established by finite element method and the axial temperature distribution was obtained. The influences of surface roughness, nominal contact pressure and axial position of contact on axial temperature distribution were analysed. Based on temperature distribution in the tie-bolt fastened rotor, the variation of tighten force was investigated. Results show that nominal contact pressure, surface roughness and axial contact arrange have different influences on the variation of tighten force with temperature.

Thermal Contact Conductance of Metallic Coated BiCaSrCuO Superconductor/Copper Interfaces at Cryogenic Temperatures

1992 ◽  
Vol 114 (1) ◽  
pp. 21-29 ◽  
Author(s):  
J. M. Ochterbeck ◽  
G. P. Peterson ◽  
L. S. Fletcher
Keyword(s):  
Vapor Deposition ◽  
Thermal Contact ◽  
Deposition Process ◽  
Thermal Contact Conductance ◽  
Experimental Program ◽  
Contact Conductance ◽  
Nickel Substrates ◽  
Deposition Processes ◽  
Cold Pressed ◽  
And Control

The effects of vapor deposited coatings on the thermal contact conductance of cold pressed, normal state BiCaSrCuO superconductor/oxygen-free copper interfaces were experimentally investigated over a pressure range of 200 to 2000 kPa. Using traditional vapor deposition processes, thin coatings of indium or lead were applied to the superconductor material to determine the effect on the heat transfer occurring at the interface. The test data indicate that the contact conductance can be enhanced using these coatings, with indium providing the greater enhancement. The experimental program revealed the need for a better understanding and control of the vapor deposition process when using soft metallic coatings. Also, the temperature-dependent microhardness of copper was experimentally determined and found to increase by approximately 35 percent as the temperature decreased from 300 to 85 K. An empirical model was developed to predict the effect of soft coatings on the thermal contact conductance of the superconductor/copper interfaces. When applied, the model agreed well with the data obtained in this investigation at low coating thicknesses but overpredicted the data as the thickness increased. In addition, the model agreed very well with data obtained in a previous investigation for silver-coated nickel substrates at all coating thicknesses.

A new method of measuring thermal contact conductance

2004 ◽  
Vol 145 (2) ◽  
pp. 207-214 ◽  
Author(s):  
M Rosochowska ◽  
K Chodnikiewicz ◽  
R Balendra
Keyword(s):  
Thermal Contact ◽  
New Method ◽  
Thermal Contact Conductance ◽  
Contact Conductance

Measurement of Thermal Contact Conductance of a Heat Shield for Gas Turbine Combustors in a Realistic Test Rig Set-Up

2012 ◽  
Author(s):  
B. Facchini ◽  
F. Simonetti ◽  
L. Tarchi ◽  
R. Abram ◽  
M. Maritano
Keyword(s):  
Gas Turbine ◽  
Thermal Contact ◽  
Operating Conditions ◽  
Heat Shield ◽  
Ceramic Fiber ◽  
Thermal Contact Conductance ◽  
Test Rig ◽  
Contact Conductance ◽  
Experimental Campaign ◽  
Set Up

This paper presents the results of the experimental campaign on the measurement of thermal contact conductance (TCC) in a realistic test rig replicating the contact between the ceramic heat shield and the liner for an ANSALDO Energia s.p.a. heavy-duty gas turbine. The designed test rig is made up of a single sector consisting of a combustor ceramic brick and a liner sector with a non-rigid ceramic fiber textile insulating layer in between, to better replicate the operating conditions of the combustor components. The experimental campaign was carried out with a steady-state technique applying an uniform thermal load on the heat shield surface. The effect of brick-holders, that in the actual combustor anchor the bricks on the liner walls, was replicated with static loads. The liner sector was tested without the brick-holder grooves first and afterwards their effect was assessed in the same test conditions; the test campaign also aimed at measuring the load cycling effect on TCC. Validation of the measured TCC was then performed with a finite element code to compare the predicted temperature profiles with the measured ones.

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