scholarly journals CFD-Guided Development of Test Rigs for Studying Erosion and Large-Particle Damage of Thermal Barrier Coatings

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Maria A. Kuczmarski ◽  
Robert A. Miller ◽  
Dongming Zhu
Keyword(s):  
Thermal Barrier Coatings ◽  
Large Particle ◽  
Turbine Blades ◽  
High Heat ◽  
Heat Fluxes ◽  
Materials Testing ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Particle Damage ◽  
Computational Fluid Dynamics Cfd

Burner rigs are routinely used to qualify materials for gas turbine applications. The most useful rig tests are those that can replicate, often in an accelerated manner, the degradation that materials experience in the engine. Computational fluid dynamics (CFD) can be used to accelerate the successful development and continuous improvement of combustion burner rigs for meaningful materials testing. Rig development is typically an iterative process of making incremental modifications to improve the rig performance for testing requirements. Application of CFD allows many of these iterations to be done computationally before hardware is built or modified, reducing overall testing costs and time, and it can provide an improved understanding of how these rigs operate. This paper describes the use of CFD to develop burner test rigs for studying erosion and large-particle damage of thermal barrier coatings (TBCs) used to protect turbine blades from high heat fluxes in combustion engines. The steps used in this study—determining the questions that need to be answered regarding the test rig performance, developing and validating the model, and using it to predict rig performance—can be applied to the efficient development of other test rigs.

scholarly journals Analysis of the energetic/environmental performances of gas turbine plant: Effect of thermal barrier coatings and mass of cooling air

2009 ◽  
Vol 13 (1) ◽  
pp. 147-164 ◽  
Author(s):  
Ion Ion ◽  
Anibal Portinha ◽  
Jorge Martins ◽  
Vasco Teixeira ◽  
Joaquim Carneiro
Keyword(s):  
Thermal Conductivity ◽  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Heat Transfer Analysis ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Barrier Coatings ◽  
Cooling Air Flow ◽  
Cooling Air

Zirconia stabilized with 8 wt.% Y2O3 is the most common material to be applied in thermal barrier coatings owing to its excellent properties: low thermal conductivity, high toughness and thermal expansion coefficient as ceramic material. Calculation has been made to evaluate the gains of thermal barrier coatings applied on gas turbine blades. The study considers a top ceramic coating Zirconia stabilized with 8 wt.% Y2O3 on a NiCoCrAlY bond coat and Inconel 738LC as substrate. For different thickness and different cooling air flow rates, a thermodynamic analysis has been performed and pollutants emissions (CO, NOx) have been estimated to analyze the effect of rising the gas inlet temperature. The effect of thickness and thermal conductivity of top coating and the mass flow rate of cooling air have been analyzed. The model for heat transfer analysis gives the temperature reduction through the wall blade for the considered conditions and the results presented in this contribution are restricted to a two considered limits: (1) maximum allowable temperature for top layer (1200?C) and (2) for blade material (1000?C). The model can be used to analyze other materials that support higher temperatures helping in the development of new materials for thermal barrier coatings.

scholarly journals Analytical and Experimental Study of Residual Stresses in Thermal Barrier Coatings Deposited on Gas Turbine Blades in Laboratory Dimensions by APS and HVOF Methods to Calculate the Optimal Thickness

2021 ◽  
Vol 3 (1) ◽  
pp. 63-67
Author(s):  
Esmaeil Poursaeidi ◽  
◽  
Farzam Montakhabi ◽  
Javad Rahimi ◽  
◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Analytical Model ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Optimal Thickness ◽  
Barrier Coatings

The constant need to use gas turbines has led to the need to increase turbines' inlet temperature. When the temperature reaches a level higher than the material's tolerance, phenomena such as creep, changes in mechanical properties, oxidation, and corrosion occur at high speeds, which affects the life of the metal material. Nowadays, operation at high temperatures is made possible by proceedings such as cooling and thermal insulation by thermal barrier coatings (TBCs). The method of applying thermal barrier coatings on the turbine blade creates residual stresses. In this study, residual stresses in thermal barrier coatings applied by APS and HVOF methods are compared by Tsui–Clyne analytical model and XRD test. The analytical model results are in good agreement with the experimental results (between 2 and 8% error), and the HVOF spray method creates less residual stress than APS. In the end, an optimal thickness for the coating is calculated to minimize residual stress at the interface between the bond coat and top coat layers.

STUDY ON PREPARATION TECHNOLOGIES OF THERMAL BARRIER COATINGS

2016 ◽  
Vol 24 (04) ◽  
pp. 1730004 ◽  
Author(s):  
TAO WANG ◽  
NING WANG ◽  
YANG LI ◽  
HAO WANG ◽  
JIE TANG ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
Turbine Blades ◽  
Thermally Grown Oxide ◽  
Thermal Barrier ◽  
Properties Of Coatings ◽  
Preparation Technology ◽  
Barrier Coatings ◽  
Gradient Coating ◽  
Nano Coating

Thermal barrier coatings (TBCs) is one of the main key technology for the high-pressure turbine blades which are the main components of the high-performance aerospace engines. It offers protection for underline metallic components from corrosion, oxidation and localized melting by insulating the metal from hot gases in the engine core. The properties and lifetime of TBCs are greatly influenced by the preparation technology, which includes plasma spraying (PS), physical vapor deposition (PVD) and laser re-melting (LM). In this paper, three technologies used to prepare the TBCs are reviewed. Resulting features of coating fabricated by each technology are also discussed such as: the porosity, the thermally grown oxide (TGO), the erosion resistance, the thermal shock and so on. Especially, it is pointed out that the performances of gradient coating and nano-coating are better than the traditional coatings. In addition, it is widely accepted that laser can be applied to re-melt the PS coating and even directly clad the gradient coating. In the future, the traditional preparation technology should be improved continually in order to enhance the coating lifetime, enhance the properties of coating and lower the cost of process. Moreover, the researches on gradient-nano-structured coatings preparation are absent and should be done with emphasis since the nano-structure and gradient structure can both benefit the lifetime and properties of coatings.

Application of an Industrial Sensor Coating System on a Rolls-Royce Jet Engine for Temperature Detection

2012 ◽  
Author(s):  
J. P. Feist ◽  
P. Y. Sollazzo ◽  
S. Berthier ◽  
B. Charnley ◽  
J. Wells
Keyword(s):  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Temperature Measurements ◽  
Thermal Barrier ◽  
Coating System ◽  
Excitation Light ◽  
Barrier Coatings ◽  
Jet Engine ◽  
Temperature Detection

Thermal barrier coatings are used to reduce the actual working temperature of the high pressure turbine blade metal surface and hence permit the engine to operate at higher more efficient temperatures. Sensor coatings are an adaptation of existing thermal barrier coatings to enhance their functionality, such that they not only protect engine components from the high temperature gas, but can also measure the material temperature accurately and determine the health of the coating e.g. ageing, erosion and corrosion. The sensing capability is introduced by embedding optically active materials into the thermal barrier coatings and by illuminating these coatings with excitation light phosphorescence can be observed. The phosphorescence carries temperature and structural information about the coating. Accurate temperature measurements in the engine hot section would eliminate some of the conservative margins which currently need to be imposed to permit safe operation. A 50K underestimation at high operating temperatures can lead to significant pre-mature failure of the protective coating and loss of integrity. Knowledge of the exact temperature could enable the adaptation of the most efficient coating strategies using the minimum amount of air. The integration of an on-line temperature detection system would enable the full potential of thermal barrier coatings to be realised due to improved accuracy in temperature measurement and early warning of degradation. This in turn will increase fuel efficiency and reduce CO2 emissions. Application: This paper describes the implementation of a sensor coating system on a Rolls-Royce jet engine. The system consists of three components: industrially manufactured robust coatings, advanced remote detection optics and improved control and readout software. The majority of coatings were based on yttria stabilized zirconia doped with Dy (dysprosium) and Eu (europium), although other coatings made of yttrium aluminium garnet were manufactured as well. Coatings were produced on a production line using atmospheric plasma spraying. Parallel tests at Didcot power station revealed survivability of specific coatings in excess of 4,500 effective operating hours. It is deduced that the capability of these coatings is in the range of normal maintenance schedules of industrial gas turbines of 24,000 hours or even longer. An advanced optical system was designed and manufactured permitting easy scanning of coated components and also the detection of phosphorescence on rotating turbine blades (13k RPM) at stand-off distances of up to 400mm. Successful temperature measurements were taken from the nozzle guide vanes (hot), the combustion chamber (noisy) and the rotating turbine blades (moving) and compared with thermocouple and pyrometer installations for validation purposes.

The Evolution of Thermal Barrier Coatings in Gas Turbine Engine Applications

1994 ◽  
Vol 116 (1) ◽  
pp. 250-257 ◽  
Author(s):  
S. M. Meier ◽  
D. K. Gupta
Keyword(s):  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Engine Performance ◽  
Design System ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Turbine Engine ◽  
Component Design ◽  
Integral Element ◽  
Plasma Sprayed

Thermal barrier coatings (TBCs) have been used for almost three decades to extend the life of combustors and augmentors and, more recently, stationary turbine components. Plasma-sprayed yttria-stabilized zirconia TBC currently is bill-of-material on many commercial jet engine parts. A more durable electron beam-physical vapor deposited (EB-PVD) ceramic coating recently has been developed for more demanding rotating as well as stationary turbine components. This ceramic EB-PVD is bill-of-material on turbine blades and vanes in current high thrust engine models and is being considered for newer developmental engines as well. To take maximum advantage of potential TBC benefits, the thermal effect of the TBC ceramic layer must become an integral element of the hot section component design system. To do this with acceptable reliability requires a suitable analytical life prediction model calibrated to engine experience. The latest efforts in thermal barrier coatings are directed toward correlating such models to measured engine performance.

scholarly journals Performance of thermal barrier coatings in high heat flux environments

1984 ◽  
Vol 119 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Robert A. Miller ◽  
Christopher C. Berndt
Keyword(s):  
Heat Flux ◽  
Thermal Barrier Coatings ◽  
High Heat ◽  
Thermal Barrier ◽  
High Heat Flux ◽  
Barrier Coatings

Developments in Processing of Ceramic Top Coats of EB-PVD Thermal Barrier Coatings

2007 ◽  
Vol 333 ◽  
pp. 137-146 ◽  
Author(s):  
Bilge Saruhan ◽  
Uwe Schulz ◽  
Marion Bartsch
Keyword(s):  
Thermal Conductivity ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Morphological Changes ◽  
Turbine Blades ◽  
Young Modulus ◽  
Thermal Barrier ◽  
Cross Sectional ◽  
Barrier Coatings ◽  
The Cross

Partially Yttria Stabilized Zirconia (PYSZ) based Thermal Barrier Coatings (TBC) manufactured by EB-PVD process are a crucial part of a system, which protects the turbine blades situated at the high pressure sector of aero engines and stationary gas turbines under severe service conditions. These materials show a high strain tolerance relying on their unique coating morphology, which is represented by weakly bonded columns. The porosity present in ceramic top coats affects the thermal conductivity by reducing the cross sectional area through which the heat flows. The increase in thermal conductivity after heat-treatment relates to the alteration of the shape of the pores rather than the reduction of their surface-area at the cross section. The studies carried out by the authors demonstrate that the variation of the parameters during the EB-PVD processing of PYSZ based top-coats alters the columnar morphology of the coatings. Consequently, these morphological changes affect primarily the thermal conductivity and eventually the Young’ Modulus which are the key physical properties of this material group. New ceramic compositions covering zirconia coatings stabilized with alternative oxides, pyrochlores and hexaluminates are addressed. Failures occurring in ceramic top coats mark the lifetime of TBC system and therefore, it is necessary that their performance should go beyond that of the-state-of-the-art materials. This context summarizes the research and developments devoted to future generation ceramic top coats of EB-PVD TBCs.

Fundamental Coating Development Study to Improve the Isothermal Oxidation Resistance and Thermal Cycle Durability of Thermal Barrier Coatings

2006 ◽  
Vol 522-523 ◽  
pp. 247-254 ◽  
Author(s):  
Taiji Torigoe ◽  
Hidetaka Oguma ◽  
Ikuo Okada ◽  
Guo Chun Xu ◽  
Kazuhisa Fujita ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Atmospheric Plasma ◽  
Zirconia Ceramic ◽  
Thermal Barrier ◽  
Temperature Oxidation ◽  
Barrier Coatings ◽  
Oxidation Properties

Thermal barrier coatings(TBCs) are used in high temperature gas turbines to reduce the surface temperature of cooled metal parts such as turbine blades[1]. TBC consist of a bondcoat (e.g. MCrAlY where M is Co, Ni, CoNi, etc.) and a partially stabilized zirconia ceramic topcoat. Usually, the MCrAlY bondcoat is applied by LPPS (low pressure plasma spray) or HVOF(high velocity oxi-fuel spray). The topcoat is applied by APS (atmospheric plasma splay) or EB-PVD (electron beam-physical vapor deposition). High temperature oxidation properties, thermal barrier properties and durability of TBC are very important to increase the reliability in high temperature service. In this study, new TBC has been investigated. The new TBC consists of a two-layered bondcoat (LPPS-MCrAlY plus dense PVD overlay MCrAlY) and the EB-PVD type YSZ columnar structure topcoat. As a result of evaluation tests, it was confirmed that the new TBC had better oxidation properties and durability than a conventional TBC system.

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