Investigation of high thermal contact conductance at low contact pressure for high-heat-load optical elements of synchrotron radiation

2013 ◽  
Author(s):  
T. Takeuchi ◽  
M. Tanaka ◽  
H. Ohashi ◽  
S. Goto
Keyword(s):  
Synchrotron Radiation ◽  
Contact Pressure ◽  
Heat Load ◽  
Thermal Contact ◽  
High Heat ◽  
Thermal Contact Conductance ◽  
Optical Elements ◽  
Contact Conductance ◽  
High Heat Load

Study on evaluation method of tube—fin thermal contact conductance

2010 ◽  
Vol 225 (2) ◽  
pp. 390-396
Author(s):  
D Tang ◽  
D Li ◽  
Y Peng ◽  
Z Du
Keyword(s):  
Contact Pressure ◽  
Evaluation Method ◽  
Thermal Contact ◽  
Element Model ◽  
Thermal Contact Conductance ◽  
Forming Process ◽  
Contact Conductance ◽  
Die Geometry ◽  
Novel Method ◽  
Tube Expansion

The thermal contact conductance (TCC) is one of the principal parameter in heat transfer mechanism of tube—fin heat exchangers. Because of the difficulties in experimental measurements, the tube—fin TCC has not been focused deeply. This article presents a novel method in evaluating the TCC of tube—fin heatexchanger. First, the tube—fin contact status is investigated with a finite-element model of tube expansion process. Distribution of contact pressure along the tube—fin interface is obtained from the simulation results. Then, experiments are carried out for the relationship between the contact pressure and the TCC. Combining the experiment result with the contact pressure distribution, the tube—fin TCC can be evaluated. Based on the method, effect of processing factors of the expansion forming process, such as expanding ratio and die geometry, are examined.

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.

scholarly journals Relationship between Dislocation Density and Macro Strain of High-Heat-Load Materials

2014 ◽  
Vol 996 ◽  
pp. 33-38
Author(s):  
Mutsumi Sano ◽  
Sunao Takahashi ◽  
Atsuo Watanabe ◽  
Ayumi Shiro ◽  
Takahisa Shobu
Keyword(s):  
Synchrotron Radiation ◽  
Dislocation Density ◽  
Aluminum Oxide ◽  
Heat Load ◽  
Fine Particles ◽  
High Heat ◽  
Diffraction Profile ◽  
High Heat Load ◽  
Ultra Fine Particles

A relationship between dislocation density and macro strain was investigated for GLIDCOP, dispersion-strengthened copper with ultra-fine particles of aluminum oxide. The dislocation density was estimated by applying the Warren-Averbach method to a diffraction profile measured using synchrotron radiation.

Beamline 14: a new multipole wiggler beamline for protein crystallography on the SRS

1998 ◽  
Vol 5 (3) ◽  
pp. 497-499 ◽  
Author(s):  
E. M. H. Duke ◽  
R. C. Kehoe ◽  
P. J. Rizkallah ◽  
J. A. Clarke ◽  
C. Nave
Keyword(s):  
Synchrotron Radiation ◽  
High Intensity ◽  
Radiation Source ◽  
Heat Load ◽  
Protein Crystallography ◽  
High Heat ◽  
Synchrotron Radiation Source ◽  
High Heat Load ◽  
The Uk

A new multipole wiggler device has been designed for the 2.0 GeV Synchrotron Radiation Source at Daresbury Laboratory in the UK. The nine-pole 2.0 T device will provide radiation for two beamlines dedicated to protein crystallography, one of which will be of high intensity. This article provides details of the design of the two stations and outlines methods being developed to combine dealing with the high heat load from the radiation while allowing both stations to be built as close to the centre of the fan as possible.

scholarly journals The effect of internal contact pressure on thermal contact conductance during coil cooling

2020 ◽  
Vol 50 ◽  
pp. 418-424 ◽  
Author(s):  
Joonas Ilmola ◽  
Aarne Pohjonen ◽  
Oskari Seppälä ◽  
Jari Larkiola
Keyword(s):  
Contact Pressure ◽  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Contact Conductance ◽  
Internal Contact

Decrease in Thermal Contact Conductance and the Contact Pressure of Finned-Tube Heat Exchangers Assembled With Different Size Bullets

2006 ◽  
Vol 129 (7) ◽  
pp. 907-911 ◽  
Author(s):  
Chakravarti Madhusudana ◽  
Wui-wai Cheng
Keyword(s):  
Contact Pressure ◽  
Thermal Contact ◽  
Finned Tube ◽  
Thermal Contact Conductance ◽  
Maximum Temperature ◽  
Contact Conductance ◽  
Maximum Expansion ◽  
Practical Limit ◽  
Differential Expansion ◽  
Increasing Temperature

The thermal contact conductance (TCC) at the mechanically bonded tube/fin interface of a heat exchanger may be controlled by varying the amount of initial expansion of the tube. However, in this case, the TCC also varies with the temperature because of the differential expansion between the tube and the fin. The objectives of the present study are to determine the improvement in TCC resulting from higher degrees of the tube expansion, to determine the variation in TCC with the maximum temperature, and to estimate the change in contact pressure with the temperature. This paper presents the results of heat transfer experiments on mechanically expanded finned-tube specimens. Experiments were conducted in an atmosphere of nitrogen. The results showed that the TCC is enhanced by increasing the degree of initial expansion. There is a practical limit, however, to the maximum expansion that can be attempted. For the direction of heat flow prevailing in the experiments, the TCC and the contact pressure of every specimen decreased with increasing temperature.

Influence of Contact Pressure on the Thermal Contact Conductance of Layered AA3003 Aluminium

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Contact Pressure ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Contact Conductance ◽  
Contact Conductance ◽  
Interface Thermal Resistance ◽  
Measurement Results ◽  
Semi Empirical ◽  
The Relationship

For the optimization of the annealing process of aluminium coils, simulation of the process is often performed. To simulate the process with higher accuracy, reliable input parameters are required and the thermal conductivity (thermal contact conductance) is one of them. In the present study, the thermal conductivity and thermal contact conductance of AA3003 alloy sheets were measured by a steady state comparative longitudinal heat flow method at different contact pressure. To evaluate the thermal conductance at the interface, thermal resistance network model' was applied. In addition, the surface roughness of the sheets was also investigated. Based on the measurement results, the semi-empirical equation for the relationship between thermal contact conductance and contact pressure was obtained

Experimental Determination of Thermal Contact in a Diode-Heat Sink Assembly

1990 ◽  
Vol 112 (4) ◽  
pp. 350-356 ◽  
Author(s):  
V. K. Maudgal ◽  
J. Kliman ◽  
J. Miles ◽  
J. E. Sunderland
Keyword(s):  
Contact Pressure ◽  
Heat Sink ◽  
Complex Geometry ◽  
Thermal Contact ◽  
Aluminum Foil ◽  
Thermal Contact Conductance ◽  
Interface Temperature ◽  
Contact Conductance ◽  
Quality Of Contact

This study examines experimentally the quality of contact of mechanical joints in a diode heat sink assembly. Steady-state contact conductance, h, is used as a quantitative measure of the quality of contact of a joint. The emphasis of the work is on determining the contact conductance, h, for a nonideal joint using a noncontact method of recording temperature distribution in a complex geometry. Thermal contact conductance for an interface is known to depend on parameters such as contact pressure, mean interface temperature and the surface roughness characteristics of the mating surfaces. The results are presented for three different conditions of the interface namely (i) the mating surfaces are bare (ii) aluminum foil is inserted between the mating surfaces, and (iii) a high thermal conductivity grease is applied to the mating surfaces. Two levels of contact pressure are used for the interface with aluminum foil. The results indicate that the contact conductance increases with the mean temperature of the interface in all the cases. At low interface temperature, the contact conductance was greatest for the bare interface conditions. At high interface temperature, the contact conductance was greatest for the aluminum foil interface condition.

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