Determination of Cooling Parameters for a High-Speed, True-Scale, Metallic Turbine Vane

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Marc D. Polanka ◽  
James L. Rutledge ◽  
David G. Bogard ◽  
Richard J. Anthony
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Low Temperature ◽  
Surface Temperature ◽  
Thermal Barrier Coating ◽  
Biot Number ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Overall Effectiveness

Facilities such as the Turbine Research Facility (TRF) at the Air Force Research Laboratory have been acquiring uncooled heat transfer measurements on full-scale metallic airfoils for several years. The addition of cooling flow to this type of facility has provided new capabilities and new challenges. Two primary challenges for cooled rotating hardware are that the true local film temperature is unknown, and cooled thin-walled metallic airfoils prohibit semi-infinite heat conduction calculation. Extracting true local adiabatic effectiveness and the heat transfer coefficient from measurements of surface temperature and surface heat transfer is therefore difficult. In contrast, another cooling parameter, the overall effectiveness (ϕ), is readily obtained from the measurements of surface temperature, internal coolant temperature, and mainstream temperature. The overall effectiveness is a normalized measure of surface temperatures expected for actual operating conditions and is thus an important parameter that drives the life expectancy of a turbine component. Another issue is that scaling ϕ from experimental conditions to engine conditions is dependent on the heat transfer through the part. It has been well-established that the Biot number must be matched for the experimentally measured ϕ to match ϕ at engine conditions. However, the thermal conductivity of both the metal blade and the thermal barrier coating changes substantially from low-temperature to high-temperature engine conditions and usually not in the same proportion. This paper describes a novel method of replicating the correct thermal behavior of the thermal barrier coating (TBC) relative to the metal turbine while obtaining surface temperature measurements and heat fluxes. Furthermore, this paper describes how the ϕ value obtained at the low-temperature conditions can be adjusted to predict ϕ at high-temperature engine conditions when it is impossible to match the Biot number perfectly.

Determination of Thermal Barrier Coatings Average Surface Temperature After Engine Operation for Lifetime Validation

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Grégoire Witz ◽  
Hans-Peter Bossmann
Keyword(s):  
Surface Temperature ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Engine Operation ◽  
Barrier Coatings ◽  
Average Surface ◽  
Barrier Coating

Assessment of ex-service parts is important for the power generation industry. It gives us the opportunity to correlate part conditions to specific operating conditions like fuel used, local atmospheric conditions, operating regime, and temperature load. For assessment of thermal barrier coatings, one of the most valuable pieces of information is the local thermal condition. A method has been developed in Alstom, allowing determination of a thermal barrier coating average surface temperature after engine operation. It is based on the analysis of the phase composition of the thermal barrier coating by the acquisition of an X-ray diffraction spectrum of the coating surface, and its analysis using Rietveld refinement. The method has been validated by comparing its outcome to thermal models and base metal temperature mapping data. It is used for assessment of combustor and turbine coatings with various purposes: Determination of remnant coating life, building of lifing models, or determination of the coating degradation mechanisms under some specific operating conditions. Examples will be presented showing applications of this method.

Development of Advance Thermal Barrier Coating in Gas Turbine

2010 ◽  
Vol 123-125 ◽  
pp. 459-462
Author(s):  
Choul Jun Choi ◽  
Jung Ki Lee ◽  
Lee Ku Kwac ◽  
Jae Yeol Kim
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Turbine ◽  
Thermal Barrier Coating ◽  
Base Metal ◽  
Surface Profile ◽  
Thermal Barrier ◽  
Metal Base ◽  
Combustion Gas ◽  
Barrier Coating

Combustion gas of gas turbine is about 1100 ~ 1300 °C. Is doing TBC(Thermal Barrier Coating) on the base metal surface to protect rotor or blade from high temperature flame. TBC system reduced heat transfer as metal base metal. TBC system is divided by bond coating of prevent oxidation and corrosion and Top coating reduced of heat transfer by high Temperature flame. The objective of this study was to development of an advance TBC system for high Temperature (>1350°C) gas turbine components. Used coating powder developed newly in coating process, and more than 1350°C by parameter control in usable coating method develop. Internal studies looked at the effect of TBC coating thickness, material chemistry, substrate composition, surface temperature and bond coat as-sprayed surface profile/particle size on technical performance.

The impact of piston thermal barrier coating roughness on high-load diesel operation

2019 ◽  
pp. 146808741989348 ◽  
Author(s):  
Eric Gingrich ◽  
Michael Tess ◽  
Vamshi Korivi ◽  
Peter Schihl ◽  
John Saputo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Thermal Barrier Coating ◽  
Engine Performance ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Engine Operation ◽  
Barrier Coating ◽  
The Impact ◽  
High Output

Thermal barrier coatings of various thickness and surface roughness were applied to the piston crown of a single-cylinder research engine and tested over a range of high-output diesel operating conditions, some near 30 bar gross indicated mean effective pressure. Three yttria-stabilized zirconia coated pistons were compared to a baseline metal piston. At each operating condition, a start-of-injection sweep was conducted to generate efficiency trends and find the optimal combustion phasing. Three variations of pistons coated with a graded-layer thermal barrier coating were tested: (1) 0.185 mm coating thickness with a surface roughness of approximately Ra = 11.8 µm, (2) 0.325 mm thickness with Ra = 11.8 µm, and (3) 0.325 mm thickness with Ra = 6.0 µm. Both coated pistons with Ra = 11.8 µm did not show any statistically significant improvement to engine performance when compared to the metal baseline piston, but did produce higher filter smoke numbers. The coated piston with Ra = 6.0 µm and 0.325 mm showed an increase of gross indicated thermal efficiency of up to 3.5% (relative) compared to the metal baseline piston for operating conditions comparable to standard engine operation and a reduction of filter smoke number back to the metal baseline. The increase in efficiency was found to correlate with additional late-cycle apparent heat release and a reduction in in-cylinder heat transfer. The very high-output conditions showed statistically insignificant changes in performance or heat transfer, which may have been related to the long injection duration used for these cases targeting outside of the piston bowl.

Determination of Thermal Barrier Coatings Average Surface Temperature After Engine Operation for Lifetime Validation

2012 ◽  
Author(s):  
Grégoire Witz ◽  
Hans-Peter Bossmann
Keyword(s):  
Surface Temperature ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Engine Operation ◽  
Barrier Coatings ◽  
Average Surface ◽  
Barrier Coating

Assessment of ex-service parts is important for power generation industry. It gives the opportunity to correlate part conditions to specific operating conditions like fuel used, local atmospheric conditions, operating regime, and temperature load. For assessment of thermal barrier coatings, one of the most valuable information is the local thermal condition. A method has been developed in Alstom, allowing determination of a thermal barrier coating average surface temperature after engine operation. It is based on the analysis of the phase composition of the thermal barrier coating by the acquisition of an X-Ray diffraction spectrum of the coating surface, and its analysis using Rietveld refinement. The method has been validated by comparing its outcome to thermal models and base metal temperature mapping data. It is used for assessment of combustor and turbine coatings with various purposes: determination of remnant coating life, building of lifing models, or determination of the coating degradation mechanisms under some specific operating conditions. Examples will be presented showing applications of this method.

Results From the Phase II Test Using the High-Temperature Developing Unit (HTDU)

1988 ◽  
Vol 110 (2) ◽  
pp. 251-258 ◽  
Author(s):  
S. Aoki ◽  
K. Teshima ◽  
M. Arai ◽  
H. Yamao
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermal Barrier Coating ◽  
Phase Ii ◽  
Thermal Barrier ◽  
Test Results ◽  
High Pressure Turbine ◽  
Barrier Coating ◽  
Two Stages

Phase II of the high-temperature turbine test was performed using the High-Temperature Developing Unit (HTDU). This unit has the same two stages as the high-pressure turbine of the AGTJ-100A reheat system. The purpose of the Phase II test was to investigate the potential of candidate technologies that may be applied to the advanced engine, the AGTJ-100B. Cooling characteristics of several cooling schemes for the first stage blades, and the performance of thermal barrier coating employed on the first stage nozzles and blades, were investigated. This paper presents the Phase II test results.

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