Film Cooling With a Thermal Barrier Coating: Round Holes, Craters, and Trenches

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
F. Todd Davidson ◽  
David A. KistenMacher ◽  
David G. Bogard
Keyword(s):  
Thermal Behavior ◽  
Film Cooling ◽  
Thermal Protection ◽  
Engine Performance ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Barrier Coating ◽  
Internally Cooled ◽  
Thermally Conducting

Little work has been done to understand the interconnected nature of film cooling and thermal barrier coatings (TBCs) on protecting high temperature turbine components. With increasing demands for improved engine performance it is vital that a greater understanding of the thermal behavior of turbine components is achieved. The purpose of this study was to investigate how various film cooling geometries affect the cooling performance of a thermally conducting turbine vane with a TBC. The vane model used in this study was designed to match the thermal behavior of real engine components by properly scaling the convective heat transfer coefficients along with the thermal conductivity of the vane wall. This allowed for the measurement of temperatures at the interface of the TBC and vane wall which, when nondimensionalized, are representative of the temperatures present for actual engine vanes. This study found that the addition of a TBC on the surface of an internally cooled vane produced a near constant cooling performance despite significant changes in the blowing ratio. The craters, trench, and modified trench of this study were found to provide much better film cooling coverage than round holes; however, the improved film cooling coverage led to only slight improvements in temperature at the interface of the TBC and vane wall. These results suggest that there is minimal advantage in using more complicated cooling configurations, particularly since they may be more susceptible to TBC spallation. However, the improved film coverage from the trench and crater designs may increase the life of the TBC, which would be greatly beneficial to the long-term thermal protection of the vane.

Film Cooling With a Thermal Barrier Coating: Round Holes, Craters and Trenches

2012 ◽  
Author(s):  
F. Todd Davidson ◽  
David A. Kistenmacher ◽  
David G. Bogard
Keyword(s):  
Thermal Behavior ◽  
Film Cooling ◽  
Thermal Protection ◽  
Engine Performance ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Barrier Coating ◽  
Internally Cooled ◽  
Thermally Conducting

Little work has been done to understand the interconnected nature of film cooling and thermal barrier coatings (TBC’s) on protecting high temperature turbine components. With increasing demands for improved engine performance it is vital that a greater understanding of the thermal behavior of turbine components is achieved. The purpose of this study was to investigate how various film cooling geometries affect the cooling performance of a thermally conducting turbine vane with a TBC. The vane model used in this study was designed to match the thermal behavior of real engine components by properly scaling the convective heat transfer coefficients as well as the thermal conductivity of the vane wall. This allowed for the measurement of temperatures at the interface of the TBC and vane wall which, when non-dimensionalized, are representative of the temperatures present for actual engine vanes. This study found that the addition of TBC on the surface of an internally cooled vane produced a near constant cooling performance despite significant changes in the blowing ratio. The craters, trench and modified trench of this study were found to provide much better film cooling coverage than round holes; however, the improved film cooling coverage led to only slight improvements in temperature at the interface of the TBC and vane wall. These results suggest that there is minimal advantage in using more complicated cooling configurations, particularly since they may be more susceptible to TBC spallation. However, the improved film coverage from the trench and crater designs may increase the life of the TBC which would be greatly beneficial to the long-term thermal protection of the vane.

Realistic Trench Film Cooling With a Thermal Barrier Coating and Deposition

2013 ◽  
Author(s):  
David A. Kistenmacher ◽  
F. Todd Davidson ◽  
David G. Bogard
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Effectiveness ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Barrier Coating ◽  
Turbine Vane ◽  
Thermally Conducting

Thermal barrier coatings (TBC’s) see extensive use in high temperature gas turbines. However, little work has been done to experimentally characterize the combination of TBC and film cooling. The purpose of this study is to investigate the cooling performance of a thermally conducting turbine vane with a realistic film cooling trench geometry embedded in TBC. Additionally, the effect of contaminant deposition on the realistic trench was studied. The trench is termed realistic because it takes into account probable manufacturing limitations. The vane model and TBC used for this study were designed to match the thermal behavior of an actual gas turbine vane with TBC by properly scaling their convective heat transfer coefficients, thermal conductivities, and characteristic length scales. This study built upon previously published results with various film cooling geometries consisting of round holes, craters, an ideal trench, and a novel trench. The previous study showed that large changes in blowing ratio resulted in negligible effects on cooling performance. Changes to film cooling geometry also resulted in minor effects on cooling performance. This study found that the realistic trench and an idealized trench perform similarly. However, the width of the realistic trench left the vane wall more exposed to mainstream temperatures, especially at lower film coolant flow rates. This study also found that the trench designs helped to mitigate deposition formation better than round holes; however, the realistic trench was more prone to deposition within the trench. The overall cooling effectiveness was similar for both trench designs and relatively unchanged from the pre-deposition performance while the overall cooling effectiveness for round holes increased due to the additional thermal insulation offered by the unmitigated deposition.

Realistic Trench Film Cooling With a Thermal Barrier Coating and Deposition

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
David A. Kistenmacher ◽  
F. Todd Davidson ◽  
David G. Bogard
Keyword(s):  
Film Cooling ◽  
Gas Turbines ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Effectiveness ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Barrier Coating ◽  
Turbine Vane ◽  
Thermally Conducting

Thermal barrier coatings (TBC) see extensive use in high-temperature gas turbines. However, little work has been done to experimentally characterize the combination of TBC and film cooling. The purpose of this study is to investigate the cooling performance of a thermally conducting turbine vane with a realistic film-cooling trench geometry embedded in TBC. Additionally, the effect of contaminant deposition on the realistic trench was studied. The trench is termed realistic because it takes into account probable manufacturing limitations. The vane model and TBC used for this study were designed to match the thermal behavior of an actual gas turbine vane with TBC by properly scaling their convective heat-transfer coefficients, thermal conductivities, and characteristic length scales. This study built upon previously published results with various film-cooling geometries consisting of round holes, craters, an ideal trench, and a novel trench. The previous study showed that large changes in blowing ratio resulted in negligible effects on cooling performance. Changes to film-cooling geometry also resulted in minor effects on cooling performance. This study found that the realistic trench and an idealized trench perform similarly. However, the width of the realistic trench left the vane wall more exposed to mainstream temperatures, especially at lower film-coolant flow rates. This study also found that the trench designs helped to mitigate deposition formation better than round holes; however, the realistic trench was more prone to deposition within the trench. The overall cooling effectiveness was similar for both trench designs and relatively unchanged from the predeposition performance, while the overall cooling effectiveness for round holes increased due to the additional thermal insulation offered by the unmitigated deposition.

A Study of Deposition on a Turbine Vane With a Thermal Barrier Coating and Various Film Cooling Geometries

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
F. Todd Davidson ◽  
David A. Kistenmacher ◽  
David G. Bogard
Keyword(s):  
Thermal Barrier Coating ◽  
Film Cooling ◽  
Stokes Number ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Barrier Coating ◽  
Turbine Vane ◽  
Engine Components

Recent interest has been shown in using synthetic gaseous (syngas) fuels to power gas turbine engines. An important issue concerning these fuels is the potential for increased contaminant deposition that can inhibit cooling designs and expedite the material degradation of vital turbine components. The purpose of this study was to provide a detailed understanding of how contaminants deposit on the surface of a turbine vane with a thermal barrier coating (TBC). The vane model used in this study was designed to match the thermal behavior of real engine components by properly scaling the convective heat transfer coefficients as well as the thermal conductivity of the vane wall. Four different film cooling configurations were studied: round holes, craters, a trench, and a modified trench. The contaminants used in this study were small particles of paraffin wax that were sprayed into the mainstream flow of the wind tunnel. The wax particles modeled both the molten nature of contaminants in an engine as well as the particle trajectory by properly matching the expected range of Stokes number. This study found that the presence of film cooling significantly increased the accumulation of deposits. It was also found that the deposition behavior was strongly affected by the film cooling configuration that was used on the pressure side of the vane. The craters and trench performed the best in mitigating the accumulation of deposits immediately downstream of the film cooling configuration. In general, the presence of deposits reduced the film cooling performance on the surface of the TBC. However, the additional thermal insulation provided by the deposits improved the cooling performance at the interface of the TBC and vane wall.

A Study of Deposition on a Turbine Vane With a Thermal Barrier Coating and Various Film Cooling Geometries

2012 ◽  
Author(s):  
F. Todd Davidson ◽  
David A. Kistenmacher ◽  
David G. Bogard
Keyword(s):  
Thermal Barrier Coating ◽  
Film Cooling ◽  
Stokes Number ◽  
Thermal Barrier ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Barrier Coating ◽  
Turbine Vane ◽  
Engine Components

Recent interest has been shown in using synthetic gaseous (syngas) fuels to power gas turbine engines. An important issue concerning these fuels is the potential for increased contaminate deposition that can inhibit cooling designs and expedite the material degradation of vital turbine components. The purpose of this study was to provide a detailed understanding of how contaminates deposit on the surface of a turbine vane with a thermal barrier coating (TBC). The vane model used in this study was designed to match the thermal behavior of real engine components by properly scaling the convective heat transfer coefficients as well as the thermal conductivity of the vane wall. Four different film cooling configurations were studied: round holes, craters, a trench and a modified trench. The contaminates used in this study were small particles of paraffin wax that were sprayed into the mainstream flow of the wind tunnel. The wax particles modeled both the molten nature of contaminates in an engine as well as the particle trajectory by properly matching the expected range of Stokes number. This study found that the presence of film cooling significantly increased the accumulation of deposits. It was also found that the deposition behavior was strongly affected by the film cooling configuration that was used on the pressure side of the vane. The craters and trench performed the best in mitigating the accumulation of deposits immediately downstream of the film cooling configuration. In general, the presence of deposits reduced the film cooling performance on the surface of the TBC. However, the additional thermal insulation provided by the deposits improved the cooling performance at the interface of the TBC and vane wall.

An Experimental Study of Thermal Barrier Coatings and Film Cooling on an Internally Cooled Simulated Turbine Vane

2011 ◽  
Author(s):  
F. Todd Davidson ◽  
Jason E. Dees ◽  
David G. Bogard
Keyword(s):  
Thermal Barrier Coatings ◽  
Film Cooling ◽  
Thermal Protection ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Blowing Ratio ◽  
Turbine Vane ◽  
Internally Cooled ◽  
Detailed Assessment ◽  
Overall Effectiveness

This study investigated the interaction of thermal barrier coatings (TBC) and various film cooling configurations to provide a detailed assessment of the thermal protection on a first stage turbine vane. The internally cooled, scaled-up turbine vane used for this study was designed to properly model the conjugate heat transfer effects found in a real engine. The TBC material was selected to properly scale the thicknesses and thermal conductivities of the model to those of the engine. External surface temperatures, TBC-vane interface temperatures and internal temperatures were all measured over a range of internal coolant Reynolds numbers and mainstream turbulence intensities. The blowing ratio of the various film-cooling designs was also varied. The addition of TBC on the vane surface was found to increase the overall effectiveness of the vane surface just downstream of the coolant holes by up to 0.25 when no film cooling was present. The presence of the TBC significantly dampened the variations in overall effectiveness due to changes in blowing ratio which mitigated the detrimental effects of coolant jet separation. It was also discovered that with the presence of TBC standard round holes showed equivalent, if not better, performance when compared to round holes embedded in a shallow transverse trench.

scholarly journals Effect of Thermal Barrier Coating on the Performance and Emissions of Diesel Engine Operated with Conventional Diesel and Palm Oil Biodiesel

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 692
Author(s):  
Navin Ramasamy ◽  
Mohammad Abul Kalam ◽  
Mahendra Varman ◽  
Yew Heng Teoh
Keyword(s):  
Thermal Barrier Coating ◽  
Palm Oil ◽  
Silicon Oxide ◽  
Engine Performance ◽  
Spray Coating ◽  
Thermal Barrier ◽  
Performance And Emission ◽  
Barrier Coating ◽  
Carbon Dioxide Co2 ◽  
Palm Oil Biodiesel

In this study, the performance and emission of a thermal barrier coating (TBC) engine which applied palm oil biodiesel and diesel as a fuel were evaluated. TBC was prepared by using a series of mixture consisting different blend ratio of yttria stabilized zirconia (Y2O3·ZrO2) and aluminum oxide-silicon oxide (Al2O3·SiO2) via plasma spray coating technique. The experimental results showed that mixture of TBC with 60% Y2O3·ZrO2 + 40% Al2O3·SiO2 had an excellent nitrogen oxide (NO), carbon monoxide (CO), carbon dioxide (CO2), and unburned hydrocarbon (HC) reductions compared to other blend-coated pistons. The finding also indicated that coating mixture 50% Y2O3·ZrO2 + 50% Al2O3·SiO2 had the highest brake thermal efficiency (BTE) and lowest of brake specific fuel consumption (BSFC) compared to all mixture coating. Reductions of HC and CO emissions were also recorded for 60% Y2O3·ZrO2 + 40% Al2O3·SiO2 and 50% Y2O3·ZrO2 + 50% Al2O3·SiO2 coatings. These encouraging findings had further proven the significance of TBC in enhancing the engine performance and emission reductions operated with different types of fuel.

scholarly journals High thickness coating of zirconium dioxide for thermal protection of metal alloys

2018 ◽  
Vol 224 ◽  
pp. 03004
Author(s):  
Irina Tsareva ◽  
Olga Berdnik ◽  
Maksim Maximov ◽  
Victor Kuzmin
Keyword(s):  
Thermal Barrier Coating ◽  
Plasma Spraying ◽  
Zirconium Dioxide ◽  
Thermal Protection ◽  
Intermetallic Layer ◽  
High Energy ◽  
Metal Alloys ◽  
Thermal Barrier ◽  
Barrier Coating

A study was made of high thickness thermal barrier coating of zirconium dioxide (up to 2 mm) formed by the method of high-energy plasma spraying on the intermetallic layer, and designed to protect the elements of the fuselage of aircraft.

Experimental and Numerical Study on the Effects of the Relative Position of Film Hole and Orientation Ribs on the Film Cooling With Ribbed Cross-Flow Coolant Channel

2020 ◽  
Author(s):  
Bingran Li ◽  
Cunliang Liu ◽  
Lin Ye ◽  
Huiren Zhu ◽  
Fan Zhang
Keyword(s):  
Heat Transfer ◽  
Relative Position ◽  
Film Cooling ◽  
Numerical Study ◽  
Cross Flow ◽  
Internal Cooling ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Numerical Studies

Abstract To investigate the application of ribbed cross-flow coolant channels with film hole effusion and the effects of the internal cooling configuration on film cooling, experimental and numerical studies are conducted on the effect of the relative position of the film holes and different orientation ribs on the film cooling performance. Three cases of the relative position of the film holes and different orientation ribs (post-rib, centered, and pre-rib) in two ribbed cross-flow channels (135° and 45° orientation ribs) are investigated. The film cooling performances are measured under three blowing ratios by the transient liquid crystal measurement technique. A RANS simulation with the realizable k-ε turbulence model and enhanced wall treatment is performed. The results show that the cooling effectiveness and the downstream heat transfer coefficient for the 135° rib are basically the same in the three position cases, and the differences between the local effectiveness average values for the three are no more than 0.04. The differences between the heat transfer coefficients are no more than 0.1. The “pre-rib” and “centered” cases are studied for the 45° rib, and the position of the structures has little effect on the film cooling performance. In the different position cases, the outlet velocity distribution of the film holes, the jet pattern and the discharge coefficient are consistent with the variation in the cross flow. The related research previously published by the authors showed that the inclination of the ribs with respect to the holes affects the film cooling performance. This study reveals that the relative positions of the ribs and holes have little effect on the film cooling performance. This paper expands and improves the study of the effect of the internal cooling configuration on film cooling and makes a significant contribution to the design and industrial application of the internal cooling channel of a turbine blade.

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