The Effect of Thermal Barrier Coating Surface Temperature on the Adhesion Behavior of CMAS Deposits

A modified form of the sequential function specification method (SFSM) is developed with specific consideration given to multiple time scales in an effort to avoid overregularization of the solution estimates. The authors extend their approach to solve the inverse heat conduction problem (IHCP) associated with the application of thermal barrier coatings (TBC) to in-cylinder surfaces of an internal combustion engine. Subsurface temperature measurements are used to calculate surface heat flux profiles. The modified inverse solver is validated ex situ using a custom fabricated radiation chamber. The solution methodology is extended in situ to evaluate temperature data collected from a single-cylinder research engine operating in homogeneous charge compression ignition (HCCI) mode. Crank angle resolved, thermal barrier coating surface temperature and heat flux profiles are produced—enabling correlation of thermal conditions at the gas-wall boundary with engine performance, emission, and efficiency metrics.

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A Study of the Effects of Thermal Barrier Coating Surface Roughness on the Boundary Layer Characteristics of Gas Turbine Aerofoils

Journal of Turbomachinery ◽

10.1115/1.3262172 ◽

1988 ◽

Vol 110 (1) ◽

pp. 88-93 ◽

Cited By ~ 2

Author(s):

R. M. Watt ◽

J. L. Allen ◽

N. C. Baines ◽

J. P. Simons ◽

M. George

Keyword(s):

Surface Roughness ◽

Reynolds Number ◽

Gas Turbine ◽

Thermal Barrier Coating ◽

Guide Vane ◽

Thermal Barrier ◽

Coating Surface ◽

Barrier Coating ◽

Nozzle Guide Vane ◽

Nozzle Guide

The effect of thermal barrier coating surface roughness on the aerodynamic performance of gas turbine aerofoils has been investigated for the case of a profile typical of current first-stage nozzle guide vane design. Cascade tests indicate a potential for significant extra loss, depending on Reynolds number, due to thermal barrier coating in its “as-sprayed” state. In this situation polishing coated vanes is shown to be largely effective in restoring their performance. The measurements also suggest a critical low Reynolds number below which the range of roughness tested has no effect on cascade efficiency. Transition detection involved a novel use of thin-film anemometers painted and fired onto the TBC surfaces.

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

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4007343 ◽

2012 ◽

Vol 134 (12) ◽

Cited By ~ 2

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.

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Numerical Simulation of Surface Temperature Fluctuation and Thermal Barrier Coating at the Piston Top for a Diesel Engine Performance Improvement

10.4271/2021-01-0229 ◽

2021 ◽

Author(s):

Yong Yin ◽

Zhijun Wu ◽

Zongjie Hu ◽

Quan Long ◽

Weiqi Ding ◽

...

Keyword(s):

Numerical Simulation ◽

Diesel Engine ◽

Surface Temperature ◽

Performance Improvement ◽

Thermal Barrier Coating ◽

Temperature Fluctuation ◽

Engine Performance ◽

Thermal Barrier ◽

Barrier Coating

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THE EFFECT OF THERMAL BARRIER COATING SURFACE TEMPERATURE ON THE ADHESION BEHAVIOR OF CMAS DEPOSITS

Journal of Turbomachinery ◽

10.1115/1.4049856 ◽

2021 ◽

pp. 1-14

Author(s):

Robert A. Clark ◽

Nicholas Plewacki ◽

Pritheesh Gnanaselvam ◽

Jeffrey P. Bons ◽

Vaishak Viswanathan

Keyword(s):

High Pressure ◽

Surface Temperature ◽

Thermal Barrier Coating ◽

Thermal Barrier ◽

Back Side ◽

Gas Temperature ◽

Front Side ◽

Barrier Coating ◽

Inlet Conditions ◽

Side Flow

Abstract The interaction of thermal barrier coatings (TBC) surface temperature with CMAS (calcium magnesium aluminosilicate) like deposits in gas turbine hot flowpath hardware is investigated. Small Hastelloy X coupons were coated in TBC and then subjected to a thermal gradient via back-side impingement cooling and front-side impingement heating using the High Temperature Deposition Facility (HTDF) at The Ohio State University (OSU). TBC front-side surface temperatures were varied by changing a constant temperature back-side mass flow, while maintaining a constant hot-side gas temperature and jet velocity representative of modern commercial turbofan high-pressure turbine (HPT) inlet conditions (approximately 1600K and 200 m/s, or Mach 0.25). In this study, Arizona Road Dust (ARD) was utilized to mimic the behavior of CMAS attack on TBCs. Accelerated deposition tests were performed where approximately 1 gram of ARD was injected into the hot side flow while the TBC surface temperature was held at various points above the minimum observed deposition temperature. Surface deposition on the TBC coupons was evaluated using an infrared camera and a backside thermocouple. In addition, an Eulerian-Lagrangian solver was used to model the hot-side impinging jet AND deposition was predicted using the OSU Deposition model. These results can be used to improve physics-based deposition models by providing valuable data relative to CMAS deposition characteristics on TBC surfaces, which modern commercial turbofan high pressure turbines use almost exclusively.

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

Journal of Turbomachinery ◽

10.1115/1.4033974 ◽

2016 ◽

Vol 139 (1) ◽

Cited By ~ 3

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.

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

Volume 7: Structures and Dynamics, Parts A and B ◽

10.1115/gt2012-68122 ◽

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.

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Adhesion Behavior of Thermal Barrier Coating on Nickel Alloy in the Bullet Shock Testing

Physics Procedia ◽

10.1016/j.phpro.2013.11.023 ◽

2013 ◽

Vol 50 ◽

pp. 139-144 ◽

Cited By ~ 1

Author(s):

Kun Zhang ◽

Lingrong He ◽

Qing Peng ◽

Chenwu Wu ◽

Guangnan Chen

Keyword(s):

Nickel Alloy ◽

Thermal Barrier Coating ◽

Thermal Barrier ◽

Shock Testing ◽

Barrier Coating ◽

Adhesion Behavior

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HOT CORROSION OF CERIA-YTTRIA STABILIZED ZIRCONIA PLASMA SPRAYED THERMAL BARRIER COATING BY EUTECTIC VANDIUM PENTAOXIDE-SODIUM SULFATE

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING ◽

10.32852/iqjfmme.vol18.iss1.83 ◽

2018 ◽

Vol 18 (1) ◽

pp. 182-192 ◽

Cited By ~ 1

Author(s):

Mohammed J Kadhim ◽

Mohammed H Hafiz ◽

Maryam A Ali Bash

Keyword(s):

Thermal Barrier Coating ◽

Hot Corrosion ◽

Monoclinic Phase ◽

Volume Fraction ◽

High Volume ◽

Thermal Barrier ◽

Air Plasma ◽

Plan View ◽

Barrier Coating ◽

Plasma Sprayed

The high temperature corrosion behavior of thermal barrier coating (TBC) systemconsisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%)bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coatwere characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt%Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC andinteraction times from 1 up to 8 h. The upper surface plan view of the coatings wereidentified for topography, roughness, chemical composition, phases and reaction productsusing scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-raydiffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed thephase transformation of nontransformable tetragonal (t') into monoclinic phase, presence ofYVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed theformation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2.The formation of these compounds were combined with formation of monoclinic phase (m)from transformation of nontransformable tetragonal phase (t').

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