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Evaluation of Alternative Thermocouple Designs for Transient Heat Transfer Measurements in Metal and Ceramic Engines
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Abstract
Finite element models of various fast-response thermocouple designs have been developed. Due to the small differences in thermal properties between thermoelements and metal engine components, standard co-axial thermocouples can measure transient temperatures of metal components within an accuracy of 98%. However, these relatively small errors in total temperature measurement translate into as high as 30% errors in indicated peak-to-peak-temperature swings for iron surfaces. The transient swing errors result in up to 30% errors in peak heat flux rates to iron surfaces. These peak heat flux errors can be substantially larger if coaxial thermocouples are used for heat flux measurements in aluminum or ceramic surfaces. Increasing the thin film thickness is a compromise solution to reduce the discrepancy in peak heat flux measured with coaxial designs in metal engines. An alternative overlapping thin film thermocouple design has also been evaluated. Due to the placement of its junction away from the thermoelements, the latter design is capable of very accurate heat transfer measurements in ceramic components.
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Citation
Assanis, D. and Badillo, E., "Evaluation of Alternative Thermocouple Designs for Transient Heat Transfer Measurements in Metal and Ceramic Engines," SAE Technical Paper 890571, 1989, https://doi.org/10.4271/890571.Also In
References
- Assanis D. N. Heywood J. B. “Development and Use of a Computer Simulation of the Turbocompound Diesel System for Engine Performance and Component Heat Transfer Studies,” SAE Paper 860329 SAE Trans. 1986
- Morel T. Keribar R. Blumberg P. N. “Cyclical Thermal Phenomena in Engine Combustion Chamber Surfaces,” SAE Paper 850360 1985
- Eckert E. R. G. Goldstein R. J. “ Measurements in Heat Transfer ” Hemisphere Publishing Corporation 1976
- Bendersky D. A. “A Special Thermocouple for Measuring Transient Temperatures,” Mechanical Engineering 75 2 117 121 1953
- LeFebvre T. Myers P. S. Uyehara O. A. “Experimental instantaneous Heat Fluxes in a Diesel Engine and their Correlation,” SAE Paper 690464 1969
- Alkidas A. C. Myers J. P. “Transient Heat-Flux Measurements in the Combustion Chamber of a Spark-Ignition Engine,” J. Heat Transfer, ASME Trans. 104 62 67 1982
- Medtherm Corporation Bulletin 500, Huntsville, Alabama May 1982
- Huang J. C. Borman G. L. “Measurements of Instantaneous Heat Flux to Metal and Ceramic Surfaces in a Diesel Engine,” SAE Paper 870155 1987
- Morel T. Wahiduzzaman S. Fort E. F. “Heat Transfer Experiments in an Insulated Diesel,” SAE 880186 1988
- Powell R. L. Burns G. W. “Thermocouple Reference Tables Based on the IPTS-68, National Bureau of Standards Department of Commerce Washington D. C. March 1974
- Assanis D. N. Badillo E. “Transient Heat Conduction in Low-Heat-Rejection Engine Combustion Chambers,” SAE Paper 870156 SAE Trans. 1987
- Li C.-H. “Piston Thermal Deformation and Friction Considerations,” SAE Paper 820086 1982
- Overbye V. D. Bennethum J. E. Myers P. S. Uyehara O. A. ”Unsteady Heat Transfer in Engines,” SAE Trans. 69 461 493 1961
- Furuhama S. Enomoto Y. “Heat Transfer into Ceramic Combustion Wall of Internal Combustion Engines,” SAE Paper 870153 1987