Thin-film thermocouples for localized heat transfer measurements

10.2514/3.836 ◽  
1996 ◽  
Vol 10 (4) ◽  
pp. 607-612 ◽  
Author(s):  
J. Lepicovsky ◽  
R. J. Bruckner ◽  
F. A. Smith
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Thin Film Thermocouples

Heat Transfer Coefficient Between Flat Surface and Sand

2011 ◽  
Author(s):  
Matthew Golob ◽  
Sheldon Jeter ◽  
Dennis Sadowski
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Thermal Energy ◽  
Test Article ◽  
Article Surface ◽  
Thin Film Thermocouples ◽  
The Heat Transfer Coefficient

Thermal energy storage (TES) systems are of interest in solar thermal power applications as an effective means of retaining energy. One of the primary issues with this type system is the exchange of thermal energy coming off the power field. In a heat exchanger, the effective heat transfer coefficient between the exchange mediums plays a crucial factor in determining the sizing of the heat exchange unit. A concept utilizing sand as a cheap particulate thermal medium was recently proposed for an alternative thermal energy storage system. The overall system will be described in some detail; however, the primary focus of this research report will be to present the experimental results measuring the heat transfer coefficient between flowing sand and a representative heat exchanger surface. To measure the heat transfer coefficient a horizontal rotating drum is used to continuously deposit sand over a centrally positioned test article. The heat transfer coefficient in this case was calculated by taking the power input divided by the known area of the test article covered by the sand as well as the measured temperature difference between the article surface and sand temperature. Calibrated thin film thermocouples attached to the test article surface as well as thin film thermocouples suspended into the sand pooling in drum satisfy the needed temperature measurements. Then, by electrically heating a known area of the test article, a heat transfer coefficient between the sand and surface can be determined. Insulation of key end surfaces and errors such as heat leak due to air as well as measurement inaccuracies were also accounted for in the experimental setup and are included in the report’s error propagation analysis. The overall results compare heat transfer coefficients measurements for a range of different sands and sizes, as well as model comparisons with known literature on the subject.

Experimental and theoretical determination of thermal stress and heat transfer for a turbine blade, using high-temperature thin film thermocouples

1974 ◽  
Vol 6 (7) ◽  
pp. 826-831
Author(s):  
D. F. Simbirskii ◽  
V. G. Bogdanov ◽  
G. N. Tret'yachenko ◽  
R. I. Kuriat ◽  
A. P. Voloshchenko
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Turbine Blade ◽  
Theoretical Determination ◽  
Thin Film Thermocouples

Thermo-Electric Properties of Thin-Film Refractory Metal Thermocouples

1994 ◽  
Vol 360 ◽  
Author(s):  
Robert G. Schinazi ◽  
Guo-Quan Lu ◽  
Frans Spaepen
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Refractory Metal ◽  
Ion Beam ◽  
Short Length ◽  
Ion Beam Sputtering ◽  
Thermo Electric ◽  
Beam Sputtering ◽  
Thin Film Thermocouples ◽  
Speed Up

AbstractThin-film thermocouples are well suited for “smart” processes where the mass of traditional two-lead thermocouples inhibits their wide utilization. However, currentthin-film thermocouples lack the robustness desired for abrasive environments. To addressthis issue, thin-film refractory metal thermocouples consisting of combinations of molybdenum, tantalum, tungsten, vanadium, or nickel were produced by ion-beam sputtering on an alumina substrate. To speed up the process of sampling a large number of material combinations, the thermocouples were made small, about 200 nm thick, 2.5 mm wide, and 12 mm long. An apparatus was fabricated to measure the thermo-electric responses of these short-length thermocouples. Materials design and heat-transfer issues relating to the applicationsand testing of these thermocouples are discussed.

Effects of Rotation on Blade Surface Heat Transfer: An Experimental Investigation

1997 ◽  
Author(s):  
Roger W. Moss ◽  
Roger W. Ainsworth ◽  
Tom Garside
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Experimental Investigation ◽  
Turbine Blade ◽  
Time History ◽  
Surface Heat ◽  
Blade Surface ◽  
Surface Heat Transfer ◽  
Effects Of Rotation ◽  
Wake Passing

Measurements of turbine blade surface heat transfer in a transient rotor facility are compared with predictions and equivalent cascade data. The rotating measurements involved both forwards and reverse rotation (wake free) experiments. The use of thin-film gauges in the Oxford Rotor Facility provides both time-mean heat transfer levels and the unsteady time history. The time-mean level is not significantly affected by turbulence in the wake; this contrasts with the cascade response to freestream turbulence and simulated wake passing. Heat transfer predictions show the extent to which such phenomena are successfully modelled by a time-steady code. The accurate prediction of transition is seen to be crucial if useful predictions are to be obtained.

Sign in / Sign up

Export Citation Format

Share Document