Effect of translucence of engineering ceramics on heat transfer in diesel engines
Abstract
This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition.more »
- Authors:
-
- Integral Technologies, Inc., Westmont, IL (United States)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab., TN (United States); Integral Technologies, Inc., Westmont, IL (United States)
- Sponsoring Org.:
- USDOE; USDOE, Washington, DC (United States)
- OSTI Identifier:
- 7267573
- Report Number(s):
- ORNL/Sub-88-22042/2
ON: DE92041384
- DOE Contract Number:
- AC05-84OR21400
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 33 ADVANCED PROPULSION SYSTEMS; 36 MATERIALS SCIENCE; DIESEL ENGINES; MATERIALS; ZIRCONIUM OXIDES; HEAT TRANSFER; CERAMICS; COATINGS; ENERGY ABSORPTION; PROGRESS REPORT; REFRACTION; SCATTERING; ABSORPTION; CHALCOGENIDES; DOCUMENT TYPES; ENERGY TRANSFER; ENGINES; HEAT ENGINES; INTERNAL COMBUSTION ENGINES; OXIDES; OXYGEN COMPOUNDS; SORPTION; TRANSITION ELEMENT COMPOUNDS; ZIRCONIUM COMPOUNDS; 330102* - Internal Combustion Engines- Diesel; 360204 - Ceramics, Cermets, & Refractories- Physical Properties
Citation Formats
Wahiduzzaman, S, and Morel, T. Effect of translucence of engineering ceramics on heat transfer in diesel engines. United States: N. p., 1992.
Web. doi:10.2172/7267573.
Wahiduzzaman, S, & Morel, T. Effect of translucence of engineering ceramics on heat transfer in diesel engines. United States. https://doi.org/10.2172/7267573
Wahiduzzaman, S, and Morel, T. Wed .
"Effect of translucence of engineering ceramics on heat transfer in diesel engines". United States. https://doi.org/10.2172/7267573. https://www.osti.gov/servlets/purl/7267573.
@article{osti_7267573,
title = {Effect of translucence of engineering ceramics on heat transfer in diesel engines},
author = {Wahiduzzaman, S and Morel, T},
abstractNote = {This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.},
doi = {10.2172/7267573},
url = {https://www.osti.gov/biblio/7267573},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {4}
}